When used for cruising for possible hook-ups and wasting time, Facebook is totally cool with Croatian authorities. When you use it for political engagement, however, they may come looking for you.

This lesson was learned by Niksa Klecak, a 22-year-old Croatian, who was held by police after he set up a Facebook group that was critical of the country's prime minister, Ivo Sanader. The group was appropriately named, "I bet I can find 5,000 people who dislike Sanader."

Free speech advocates are already lining up to defend Klecak, saying that the arrest is a "notorious abuse of police for political purposes," and that the country is squashing online debate. Croatian police, meanwhile, say that they only arrested Klecak because he depicted Sanader wearing a Nazi uniform (swastikas and other symbols from the Reich are banned under Croatian law).

If the Croats were trying to squelch protest, this probably wasn't the best way to go about it. The incident has outraged other Facebookers, who have subsequently organized protests and new groups against Sanader. A group called "Search my flat, you Gestapo gang, Croatia is not a police state" has emerged, and it's already got over 2,600 members.