"tagging" is such a load of shit. The perpetrator is most likely a schoolkid - he'll probably get caught eventually, with his hood up and cans in his bag.
In regards to graffiti in general, I like legal graffiti when appropriately positioned - it can be really aesthetically pleasing and add character to a location.
The only illegal graffiti I approve of is Banksy - the guy's a genius!
What about hutch?
+ many more decent artists (who aren't as famous)