The security men used to be highly selective in whom they chose to rescue in the event of trouble. He then disappeared, presumably to find someone worth rescuing. Newcomers still find it bizarre to hear two MPs at each other's throat using language more akin to a Regency gavotte than a bear garden. But visitors should remember the strict rules which govern the public galleries. No snogging, no talking, no singing, no smoking, no writing.
Rioting is responded to with a heavy hand.
And if you were thinking of bringing your knitting for a quiet afternoon in the Strangers' Gallery, forget it. I have seen many a stitch dropped as old ladies have been summarily ejected for indulging in the heinous practice of one plain and two perl, casting off and casting on while the Commons is in session.