And for two reasons, the first of which is that university lecturers are not trained in the relevant sorts of observation and the second of which is that there is no particular reason to single out any one sort of extremist over another for monitoring. Why should lecturers pay particular attention to Islamic extremism as opposed to National Front extremism or indeed Animal Rights extremism? All of these political beliefs are potential sources of mayhem - there was a major bust of racist terrorists only the other week.
The reason it is a bad idea is also quite simply that academics make bad police spies, and I can offer actual evidence of this apart from my idealistic belief that combining academia and the laying of informations ia a bad idea.
When I was a young post-grad, I was up for a fellowship at Oxford which I did not get because the politics don at my college asked a lot of awkward questions in the interview directed at the idea that I was in some sense a Marxist. ( I had been involved in sitins, and was writing on William Morris. The point was that I was, and am, vaguely Marxisant, but have been profoundly hostile to Leninism ever since I read the works of Vladimir Ilyich at the age of seventeen or so.)
Later on, when I was leaving the civil service, I was left alone in a room at one point, and managed to sneak a peek at my personnel file. And discovered that I had nearly been appointed to the Foreign Office rather than Health, but that the deciding factor against had been a letter from the same Polish emigre politics don alleging that I was probably a sleeper agent for one of the Trotskyite groupuscules.
The same letter is presumably on file with the other agencies of the state - my impression from the quick glance was that he had not originally directed it to the Civil Service Selection Board.
The one consolation I have in this story is that the same don was presumably instrumental in the appointment to MI5 of one of my contemporaries, Michael Bettany, a right-wing loony who had a sudden change of heart and offered his services to the KGB. The KGB assumed he was a plant and informed on him, and he ended up doing serious time.
I like to think that Pelch was taken less seriously by the authorities after that.
( Bettany was someone I seriously disliked, and his trial and imprisonment caused me much Schadenfreude; I was in hospital at the time, and seriously sick, and the news caused me to break many stitches. It was worth it.)
What is presumably going on is that the security services are too cheap to teach themselves how to understand the codes of Islamic radicalism. Heaven knows they have always been pretty dense in their understanding of the Left and the traditional Right.
It is not the job of academics to make up for their intellectual incompetence.