Arrest warrants were issued on Tuesday General Prosecutor Talaat Abdullah for members of the “terrorist ” Black Bloc group. Although very little is known about the group, reportedly dedicated to fighting Islamists, in the chaotic world of Egyptian politics it has caused hysteria.
President Mohamed Morsi's assistant for foreign affairs, Essam el-Haddad, wrote on his Facebook page that the Black Bloc was guilty of "systematic violence and organized crimes across the country." The Muslim Brotherhood website Ikhwan Online added its voice, accusing the Black Bloc of being a Christian radical militia. 
As reported in an article titled “The Black Bloc must die,”  Islamic Jihad and Gamaa Islamiyya have also issued threats. Jama'a al-Islamiya Mufti Abdel Akhar Hammad is quoted as saying “God orders us to kill, crucify or cut off the hands and feet of those who spread mischief on earth… The president must give that order.” Videos by so-called "Islamist militias"  have threatened to attack these “enemies of Islam.”
The “revolutionary” media however has come to the Bloc’s defence. Al-Watan newspaper warned the the Muslim Brotherhood may hire thugs to attack mosques and then blame it on the Bloc.
The Iranian-run FARS news agency, meanwhile, has waded in in an attempt to act as the voice of reason. It claims the Black Bloc is the result of a conspiracy to cause chaos in Egypt, formed in collusion with Mossad and the Dubai police chief.
This is all despite the fact that there is no clear evidence the bloc is not just anyone who owns a black mask. The group first made its appearance in a YouTube video on Thursday, where it claimed "We are… seeking people's liberation, the fall of corruption and the toppling of the tyrant."
Confusingly, although the group claims it does not deal with the media, social media accounts have sprung up here , here  and here, and people claiming to be from the group have appeared in Al Watan newspaper.
Two (If I had to guess, 16-year-old) members also went on the private, "revolutionary" Tahrir TV channel  and explained that their enemies are the Ministry of Interior and the Muslim Brotherhood, but that acts of violence and arson had been carried out by infiltrators not belonging to the group. The Facebook group itself immediately denied that the two masked teenagers on TV were members, and accused the station of staging the appearance to boost their audience.
All this has inspired weary cynicism from some Egyptian commentators. Lindsey adds :
The whole Black Bloc phenomenon is pretty silly. It's a symptom of the immaturity, lack of foresight and drift from peaceful (and seemingly fruitless) protesting to glamorized, indiscriminate, anti-authoritarian violence.
Mahmoud Salem in the Daily News Egypt  has called the group a “glorified media invention”:
Luckily, we don’t have to worry about the Black Bloc‘s negative effect for long. Since anyone can be a Blockhead by virtue of having three friends who will join him in wearing black masks or their mum’s black nylon stockings, and since there are no real rules or structure to the group, offshoots and splinter groups will start forming immediately.
I personally cannot wait for the emergence of the Grey Bloc, their political arm that they will immediately disavow, or the green bloc, their fundamental Islamist offshoot, or the Pink Bloc, their radical feminist wing.
Suddenly the anarchic group is spread like fire across the country through out the governorates. Since when anarchism is popular in Egypt let alone how a group like that to plan and organize itself in this way!!
With sales of black masks now on the up in Tahrir Square we could be seeing a lot more of this group.