Cornered by the furor, Sanader issued a statement Thursday, asking Interior Minister Tomislav Karamanko and Police Chief Vladimir Faber to "submit a report on the latest events and arrests in Zagreb and Dubrovnik, and to take appropriate steps if police did not respect regulations."
"By arresting several Facebook activists and by searching their computers, the Croatian police behaved in the best manner of the Chinese Secret Service," Croatian journalist and writer Boris Dezulovic told ABCNews.com. "Perhaps the police are only trying to identify the other 119,999,999 collaborators on the infamous Facebook."
The arrests so far show that police in Croatia have been tracking political protesters online, even through social networks, to arrest them and deter their online complaints. The Croatian journalists' association called on the government and police to "stop the repression and search for those responsible within its ranks."
"It is especially annoying that the premier at first justified the police action by using an excuse that it was to prevent hate speech," said an association statement.
"A social network like Facebook has focused on getting real people to share real information and to use features like groups and events to organize real world activities. That's why it is so popular in the Balkans," said web guru Marko Jevtic, the head of the popular emportal.co.yu.
The influence of Facebook on political life in national and global communities has been rising. In June, Egypt considered blocking Facebook after anti-government protests in April and May were coordinated via the site.
A protest held in 190 cities across the world in February against the activities of the Columbian rebel group FARC was also organized through a group on Facebook that gathered more than 12 million people.
And in Italy similar groups have lashed out against Prime Minister Silvio Berlusconi for his remark about Barack Obama's "suntan."