Around the corner from the alleged drug-dealers' house, 100 people gather in the darkness and rain. A scout is sent ahead to see if the "dealers" are at home. He runs back: "D's in the house. L's dealing in the children's park at the top of the street." The crowd lift their placards and prepare to march.

A small bald man steps forward to address them: "The boys we're visiting are heavily involved in the drugs' trade. Hardcore criminals also use the house. We're delivering a letter demanding they stop. If any of you are wearing hoods or scarves, take them off. We've nothing to hide."

And so Concerned Families Against Drugs (CFAD) and their supporters set off through the long, hilly streets of Ardoyne, in north Belfast, which suffered so much during the Troubles. "Years ago," says one protestor, "we wouldn't have had to do this. The IRA sorted out scumbags."

"We're here as mammies, to protect our children," says one of three women. "The drugs problem is huge. The cops do nothing."

The marchers say there's been an explosion of drugs on to the streets of Ardoyne and other working-class republican areas. Robberies and burglaries are also spiralling as young people turn to crime to finance their addiction. There have been nine marches on alleged drug-dealers' homes in recent months. This is the first time a journalist has been present.

The crowd are heading to a house in Farringdon Court where they say D and L sell "coke, blow and anything they can get their hands on". D's brother 'Scar' allegedly kicked a local man to within inches of his life outside the Shamrock social club. There are drug-fuelled rave parties in the house every weekend, one protestor says: "All sorts of lowlifes are in and out of it. These people are on the move as much as Osama bin Laden."

The protestors deliver leaflets to every house in the street informing them they're taking action against "criminal elements terrorising our community". "Fair play to you," one resident says. When they reach the alleged drug-dealers' house, it's in darkness. The front door is ajar as though someone has fled rapidly. The marchers knock but nobody answers. They think they see a shadow upstairs, somebody hiding in the front bedroom.

One protestor enters the living-room. He leaves a letter on the mantelpiece warning the inhabitants to cease their activities. Other protestors walk into the garden and cover the downstairs windows with 'Ardoyne says No to drugs' placards.

As the crowd walks away from the house, the Police Service of Northern Ireland (PSNI) arrive. "Here come the monkeys!" somebody yells. "Typical cops – on the scene to protect drug-dealers in minutes, never there for decent people," somebody else shouts. The PSNI films the departing crowd.

The protestors are mainly young and middle-aged men. Sinn Féin opposes such actions, describing them as reactionary. It urges people to work with the PSNI. Yet among the marchers are ex-IRA prisoners, including Martin Óg Meehan, son of a renowned dead IRA commander, and Basil Hardy, who served 17 years in Long Kesh for an IRA double murder.

There are non-political residents there too. "Love, don't feel sorry for the rats in that house," says a middle-aged man from Holmdene Gardens. "They'd punch you in the face and steal your handbag. The drug-dealers here have beaten old men's teeth out. They've used hammers on their victims. These people aren't fit to crawl under a stone."

Sordidness

CFAD claims some local drug-dealers' activities rival those of UDA commander Johnny Adair's old 'C' Company for sordidness. Formed last October, CFAD has 80 members and claims to have collected 5,000 signatures supporting its activities from residents in the greater Ardoyne area. "The drug dealers were out of control," says CFAD spokesman Dee Fennell.

"A 14-year-old owed one dealer [whose name is known to the Sunday Tribune] £500. The wee lad couldn't pay him so the dealer tied him to a kitchen chair and told his parents he'd be shot if they didn't get the cash. The parents went to the credit union. They brought the money to the drug dealer's mother to try to shame her over her son's activities. She said, 'Isn't it awful?', then took the money.

"Other teenagers go to the doctor's and say 'I'm nuts' just to get put into a mental institution to escape the dealers." The drug-dealer who tied up the 14-year-old was later kneecapped. CFAD say they don't know who was responsible. They say that, following their marches, this man was among 25 dealers who went to Holy Cross church in Ardoyne, confessing his activities to a priest and promising to 'reform'.

Other drug-dealers have hit back. The cars of some CFAD members and their families have been attacked with acid and windscreens smashed. CFAD member Aidan Ferguson says they've dismantled five cannabis factories: "They were elaborately set up with lights, heating tubes and sprinkler systems. It was like walking into the Apollo space station.

"One house stank from the cannabis plants. There were five wee children living with the drug-dealers. Wet towels had been stuffed at the bottom of doors to try to contain the smell to certain rooms, but the whole place was putrid. It's sick to make kids live like that."

CFAD records its activities, and that of alleged drug-dealers, in a black book which it showed to the Sunday Tribune: "KD – flat raid. MC – letter. TD – handed in dope. G admitted drug-dealing, says he's stopped. Met Cockroach. T O'G confessed chapel. TMcK and DF barred from everywhere."

A boycott similar to that which British soldiers faced in republican areas during the Troubles is imposed on dealers who are barred from local shops, pubs, cafes and taxis. The reaction of drug-dealers' families varies. Aidan Ferguson says: "Some are gutted when we talk to them, others are in denial, and plenty don't care. Some wives, girlfriends and parents are bought off with plasma TVs and holidays from drugs money."

Cockroach

The family of Cockroach falls into that category, one CFAD member says. "Cockroach flew his whole family to Cancun for his wedding. He boasts that he's put £100,000 of coke up his nose. He's bought several businesses with drugs money. His mother tells everybody: 'My son's a financial adviser'."

Some Sinn Féin-linked paid community workers denounce CFAD. "I call them 'community inactivists' – these people in their comfortable positions who are against us taking control of our lives," says Martin Og Meehan. "They think only they're fit to lead. Those who accuse us of wearing hoods by night don't need hoods – they're invisible except on pay day."

Aidan Ferguson says Sinn Féin suggestions to tackle the drug problem amount to "a toothless tiger talking-shop where we all effectively go home, pull down the blinds, and turn up the telly". The only way to influence dealers is "to have a 100 protestors at their doors". Dee Fennell doesn't understand why Sinn Féin is against CFAD's marches when "the party has spent its life marching".

After the CFAD picket, the group takes the Sunday Tribune to the Shamrock social club to watch CCTV footage of an attack outside the premises in which some inhabitants of the house picketed earlier that night were allegedly involved.

"After the funeral of a stillborn baby, some mourners got high on drugs," says Aidan Ferguson. "They tried to get into this club but a member, Brian McCartan, who was standing outside, refused them entry because they were smashing bottles. They laid into him. They broke his jaw, jumped off railings onto his head, and left him unconscious.

"These people then went to party in a house in Eskdale Gardens. They turned on one of their own, stabbing him with a pitch fork and drowning him in a bath. Thinking he was dead, they wrapped him in carpet and put him in a wheelie bin to be collected by the binmen the next day. It was like something out of Pulp Fiction."

One drinker in the Shamrock says: "Personally, I'd put these people in the electric chair." His friend adds: "An electric chair with low voltage so it would take three weeks to kill them."

Ex-IRA prisoner and Shamrock committee member Basil Hardy gave the PSNI the CCTV tape of Brian McCartan's attack: "Cooperating with the police went against my natural instincts, but the attack on Brian was so horrendous that had my own son been involved, I'd have handed over the tape. Yet nobody was arrested for the attack. The PSNI claim the footage wasn't clear. It was perfect. The police are protecting criminals – that's why CFAD exists."

Some residents claim local drug-dealers go unpunished because they're police informers. Others say the PSNI "are just clowns". But regardless of the PSNI's alleged shortcomings, critics insist CFAD has no moral or community mandate. The group has been described as a self-appointed, anonymous gang making decisions without due process and acting on flimsy evidence.

Aidan Ferguson denies this: "When people come to us with information, we investigate it thoroughly to ensure nobody is pursuing a personal vendetta. Evidence must be corroborated.

"Are we vigilantes? If a vigilante is somebody who wants a better life for their community, who wants to expose the scourge of drug-dealing then, yes, we're vigilantes." He says the group has never used violence, against people or property, during its pickets.

'Disgruntled republicans'

It's been suggested that a paramilitary influence lurks behind CFAD and the group is really a collection of disgruntled republicans. Spokesman Dee Fennell says: "Some people in CFAD are ex-IRA and INLA prisoners because our membership reflects the local community. We aren't a flag of convenience for any organisation."

Dee Fennell says residents in other areas – the Lower Falls, Lenadoon, New Lodge, Twinbrook, the Market, Short Strand, and Lower Ormeau – have asked CFAD for help: "We're considering plans to develop a community-based anti-drugs network across the city. People in Limerick or Dublin must wish they'd groups like ours to tackle their current problems."

CFAD believes life in Ardoyne will rapidly deteriorate without radical action. "Drug addicts are running around like zombies, foaming at the mouths with saliva. They don't know what they're doing. They even tried to overturn a chip van outside the Shamrock," says Aidan Ferguson.

"Wee girls working in hairdressers or bars for a few quid an hour are standing in fear of some c**t jumping over the counter with a butcher's knife to rob them. I don't want Ardoyne to sound like the Rocky Horror Show. It's a proud community, but about 50 drug dealers are trying to turn it into sewer. We won't let them. Since our protests started, there's been a dramatic improvement on the streets."