Politicians often ask for silly things in connection with technologies they don't really understand, to achieve goals they don't really expect to achieve, just in order to look good to a certain part of the electorate.
Consider an analogy between modern social media sites and something like a phone network or postal mail service. What would happen if a politician suggested that phone companies or their national postal service should be required to monitor all communications for some vaguely-defined concept of suspicious activity, and then when something was flagged, have it reviewed by a human and if deemed inappropriate cut off the spread within X hours? It would be considered an absurd suggestion by just about everyone, for being impractical, expensive, intrusive, unreliable and of questionable benefit.
And yet, politicians keep suggesting that social media companies should be able to do almost exactly that. There are demands that these companies magically detect any sort of inappropriate content on their systems, and then remove it quickly. Small details like subjectivity, privacy and practicality never seem to feature in the press conference, though.