Counter-Terrorism and Border Security Bill

Further to the point made by my hon. Friend the Member for Bermondsey and Old Southwark (Neil Coyle), I was very concerned to hear, when the companies appeared before the Home Affairs Committee, that they are not routinely searching even for the basic list of all proscribed organisations. I accept that some of this is stuff is in quite a grey territory and may sometimes not be picked up by machine learning, but one would expect that they, at a very basic level, would be searching for the names of proscribed organisations. I have found multiple examples of such content, including from Northern Irish terrorist organisations and others, on all these platforms that is not being removed even by the most basic checks. Why can we not compel the companies to do this?