Historian Diarmaid Ferriter has become the latest victim of online identity theft after a fake Facebook page was set up in his name.

Ferriter said he was extremely angry after learning of the page which described him as a "skinhead".

"Of course I'm angry about it, I'm raging. A colleague just got in touch with me asking was it me because they were getting messages supposedly from me. It had all my details on it and, really, there must be someone very sad out there with too much time on their hands."

Ferriter said the impersonator was "up to no good" connecting with other well-known historians and writers while spreading "offensive material".

"My colleague knew it wasn't me by what was being said, and by the slagging, so I have got in touch with Facebook to put an end to this. It's just ridiculous," he said.

The page was taken down after Ferriter complained to the management of Facebook .

"The fact that someone could sit down for that amount of time and actually go to all that bother is a little bit scary. It takes time to sit down and set those accounts up, and then to do all the connections and write all the details, so I am very surprised that someone has gone to all that effort in the first place," said the historian.

The Facebook impersonations come as "Madam Editor", the Twitter account set up to satirise Irish Times editor Geraldine Kennedy, continues to ruffle feathers. The Twitter account is now back online after having been temporarily taken offline following what was understood to be a vigorous campaign by the Irish Times. According to Twitter guidelines: "An account's profile information should make clear the creator of the account is not actually the same person or entity as the subject in the parody/commentary." The account name is now under 'notGeraldineKennedy', and continues to regularly tweet the editor's "thoughts".

A blog called "Madam Editor's Musings" which, too, was set up in Kennedy's name has also been removed and has not been put back online.