Mikey4444,
Yes, that is what I was refering to when I said the police monitor open air speeches. Hamza was prosecuted but (I don't think) it was for anything said in public. At yhe trial we learned of his links to the security services....
// London-based imam Abu Hamza al-Masri starts working with two branches of the British security services, the police’s Special Branch and MI5, the domestic counterintelligence service. The relationships continue for several years and there are at least seven meetings between Abu Hamza and MI5 between 1997 and 2000. Based on records of the meetings, authors Daniel O’Neill and Sean McGrory will describe the relationship as “respectful, polite, and often cooperative.”
Rhetoric - One theme in the meetings, which take place at Abu Hamza’s home and a mosque he runs in Finsbury Park, is that the security services tell Abu Hamza that they do not want any trouble and ask him to tone down some of his more inflammatory comments. Abu Hamza listens politely, but always replies he is committed to jihad. However, over this period Abu Hamza’s rhetoric changes subtly, and he begins attacking “Zionists,” rather than simply “Jews.” Abu Hamza will later say that he asks security officers if his sermons are inappropriate, and they reply, “No, freedom of speech, you don’t have to worry unless we see blood on the streets.”