They let people waste money and resources on building Death Traps that drive people insane before they die of starvation/thirst, then make stupid judgements like letting a paranoid detective into their group.
This actually DOES sound like something that any self-respecting villain would want to be a part of.
It's a rich, good ole boys club that covers their members tracks for the most part. Xanatos got, what, six months for something that could have netted him life? Bluestone used his to protect Eliza and the gargoyles. It seems that as long as it didn't hit major news networks or have too many witnesses they could make events just not happen.
That would really explain a lot, though Bluestone kind of played it up, if that was the case. "They control EVERYTHING!"
Also, are you talking about Awakening? Because they could only book him for the charges related to the stolen property & destruction of property. Elisa couldn't exactly go, "Oh, & he tried to murder these mythical beasts that don't actually even exist in mythology."
Plus, even if she did, silly or not, The Goliath Chronicles made a valid point--the modern American laws don't really apply to gargoyles.