The Czech Embassy in Washington D.C. provides an interesting link to: http://www.prague2001.com/guide.htm which is written and edited by a Prague Local... An excerpt from the web site RE: Crime follows...

CRIME. Is Prague a safe city? Yes. It is not like we do not have crime here but if you know what to do and where not to go you are fine and safe. In the center it is OK, even in the night. I would just not recommend to go to Perlova (that is a street) and to the park around Main railroad station (which we call Sherwood). There is one thing you should pay attention to and that is pocket stealing. Here in Prague there are organized groups of Romanian and Gipsy kids, even a few groups of adults and they specialize in stealing valuables from the tourists. How? Usually they choose a very crowded place (like public transportation- tram#22), get behind you and steel your purse or something else. How can you protect from these people? It is very easy. Do not take with you a lot of cash, do not put your purse into your back pocket and if you have handbag than put a hand on it. I hope you won't have any troubles.

I've been to Prague a number of times, and will be traveling there with my family for an extended stay of almost 3 weeks next month. I think that the web site mentioned has many worthy things within that should be copied for reference. ^