You sometimes hear Facebook founder Mark Zuckerberg talking of his noble ambition to "connect the world", but every country with internet access has its favourite social network, and what's galling for Zuckerberg is that it's not always his.

Let's hear it for the websites pluckily holding out. The popularity of both QZone and RenRen within China doesn't count; Facebook is banned due to government restrictions. Iran, however, chooses to embrace, not Zuckerberg's baby. In western Europe, the Netherlands is a lone state battling on all fronts with its Hyves service, while Russia and a number of its former republics shun Facebook in favour of V Kontakte, Draugiem or the wonderfully named Odnoklassniki. But this lot will inevitably succumb sooner or later, and it's Brazil and Japan that are proving Facebook's most stubborn opponents. Orkut, a social media site operated by Google, has been the most popular in Brazil for years; many reasons have been offered for its dominance, one of the most compelling being that it's easier for Portuguese speakers to say. But Japan is another thing altogether.

Barely 2% of the online Japanese population use Facebook. Their loyalties are divided between three sites: Mixi, Gree, and Mobage-Town; all offer the kind of anonymity and pseudonymity Facebook doesn't allow, and as a result a privacy-conscious Japan has given the world's biggest social media site a wide berth. Japanese citizens seem to use the medium differently; for example, one recent survey shows that half of respondents know none of their online acquaintances in real life. And that's a cultural difference that Facebook may never be able to get past.