Anonymous hacktivists have been busy today carrying out attacks on the Tunisian government site located here (IP address: 18.104.22.168). The site is still down as of the publication of this update, and has been down for several hours.
According to IRC chats with various Anonymous members who appear to be well-informed regarding current events in Tunisia, the motivations for the attacks are numerous, ranging from Tunisia's general and long-standing affinity to Internet censorship, to recent riots in Sidi Bouzid and surrounding towns being covered by various media sources.
Another relatively recent act of censorship that seems to have served as the basis for the present call to arms is the Tunisian government's decision to censor online access to Wikileaks and other whistleblowing sites (like TuniLeaks) that make reference to Tunisia or contain certain keywords that might suggest reference to Tunisia.
The Anonymous group, while diverse, intractable and virtually indefinable in terms of a steady membership class, is nevertheless united in its ideals pertaining to freedom of expression and a collective distaste for censorship, inspiring this most recent declaration:
The Tunisian government wants to control the present with falsehoods and misinformation in order to impose the future by keeping the truth hidden from its citizens. We will not remain silent while this happens. - Anonymous
There have been rumors of possible imminent attacks on 3 further Tunisian sites but they do not appear to be in progress at this time.
Update 2 :
The following sites have also been taken down: www.marchespublics.gov.tn and www.pm.gov.tn. As of 9:05 Eastern Standard Time, the former site displayed this message. This is the welcome page for Mohamed Ghannouchi, the Tunisian Prime Minister. A cached version of the page can be viewed here.
Go to the third update, containing a more exhaustive list of sites taken down.