In Brief :This Video shows a 3rd party (Hiding between protestors or on the roof tops of the surrounding buildings around tahrir)who were responsible for inducing violence between the protestors & the police.Even after the army intervened & managed to set up a buffer zone (between the protestors & the police ), this organized group of thugs kept on attacking, even after 7 failing attempts in reaching a mutual peace agreement between both ends.(They successfully achieved in promote violence every time). You can even see several other protestors who are trying to convince them to stop throwing stones & Molotov cocktails.The other sad thing is that, along side these thugs are kids/teenagers who are taking part in this assault. Most of these thugs have been also paid upfront to fulfill other people's interests.