A report by Tim Stevens and Peter Neumann for the London-based International Centre for the Study of Radicalisation and Political Violence (ICSR) analyses each of the available ISP-based filtering solutions and concludes that they are ineffective in the fight against terror. A hybrid filtering scheme was rated the best, but it is ineffective against dynamic content such as chat pages and instant messaging, and had political implications because it required the existence of a blocklist of censored pages. The report instead advocates the use of takedown notices for extremist content, and prosecutions to "signal that individuals engaged in online extremism are not beyond the law".