My problem isn't with people making themselves audible, it is with those bastards who abuse amplification to make sure that other buskers can't work. The Kelly Family used to do that in Germany. When busking gets reduced to the level of every ass trying to bray the loudest, no one will be interested in listening to us. The other problem is that an increasing number of towns will be closed to buskers.
I should also point out to Chris B that I never ask for money when busking on the basis that I need it. I ask for money on the basis that I am entertaining people and deserve it.