Incorrect. Crossbows are not illegal to own in the UK. My family and I own a variety of bows and crossbows.
If the police want to shut down riots, use an LRAD. I’m amazed that the entire UK doesn’t have just one.....
http://www.youtube.com/watch?v=QSMyY3_dmrM
http://www.youtube.com/watch?v=0F7bvhllDeI