Russian prison tattoos have a long and fantastic history, if you want to know more I highly recommend you get your hands on a copy of the Mark of Cain a documentary film on Russian Prison Tattoos. I checked in with Roman Belenky, when it comes to Russian Criminal Tattoo Culture this guy knows his дерьмо. Roman also runs "MIR" a great website you should check out if you are into unique clothing.
About the guys tattooing Russian Criminal images on themselves, I wouldn't really say anything positive about that. A lot of those tattoos had to be earned, have deep meanings behind them that you should live by and believe in before you tattoo something like that. Basically its just out of respect for those people that lived that life that a normal cat shouldn't tattoo those images. Basically thats all I can say about that. Thats kinda one of the reasons why I made the shirts. I think its better to get a shirt if you like the Art of Russian Criminal Tattoos, than to tattoo it on your body. After the books came out I started seeing young kids popping up with Russian Criminal tattoos. I thought it would've been better for them if they got a shirt instead.