I took my son to McDonald's outside King's Cross station and we couldn't use the toilets as there was a guy shooting heroin in there, shouting in a language I did not understand. Everywhere in the area were beggars, junkies and shifty characters, and that was at 1 pm. I dare not imagine what it is like at night. Yes, they are parasites and if the UK were governed by leaders who cared about their people, they would not be there.
Now back on topic.