I don't agree with sites like this.

Criminals tend to be people who have little to lose. Once you have seen the inside of a prison your life changes. You become a person that does not fear the authority's as much as a person who has something to lose.

If you involve your self in their world be sure to have a blanket of protection the fact police officers are police. Gives them the detachment the criminal understands. Should you interfere with criminals directly they will see you as a target. They could take any action you take against them personnally.

I worked a city centre for years I got to know all of the city's pickpockets, shop thieves, raiders, violent offenders, bag snatchers. When I walked though the city on a fine summers day going to the pub. That's all I saw, these people in essence it robbed me of my city and gave me their city. One which everything was dark and basically unpleasant.

These people are not worth knowing or looking up they just infect you with their way of life. If its your job you can shake them off at the end of the day .

The Talmut Says to live well is the best revenge.