The UK Home Secretary Theresa May is to outline plans this week of a "national blocking list" of websites that break the law when it comes to terrorism and inciting extremism.
This is all part of refresh of the government's Prevent strategy, which was launched in 2007 to counteract homegrown terrorism.
May believes that a screening of websites in places like schools and libraries is essential to the UK's well-being and would weed out radicalisation.
"We do not yet have a filtering product which has been rolled out comprehensively across Government departments, agencies and statutory organisations and we are unable to determine the extent to which effective filtering is in place in schools and public libraries," said May.
Article continues below
Currently The Counter Terrorism Internet Referral Unit (CTIRU) looks after blocking illegal sites on the web, but May hopes to ramp this effort up with a new strategy.
May is also critical of many universities in the UK, which don't monitor web traffic to see if extremist sites are being visited.
The new strategy document is being backed by YouTube and AOL.