there are some crimes when snitching is okay. If the neighbor likes to rape infants, then yes, it's perfectly acceptable to report him to police or just tie him to a slab and pull a Dexter on him.
DUI is cool to those in the bar having fun. To the people coming home from work, smashed on a bridge because the drunk postal carrier had to pee and was in a rush with a 1.4 or whatever.... not so cool.
some crimes are just so egregious that snitching rules don't apply. "I'm really into skullfcking metally handicapped people in wheelchairs" = snitching really is okay.