Anyone who gained control of one of Chris' online accounts (email, PSN, etc.) without his permission would be in violation of US law. Regarding the activity of the trolls, that's about the only crimes committed, but it could be very difficult to specifically charge anyone if they took any security precautions to remain anonymous. At the time these incidents occurred, maybe the Chandlers could have pursued charges, but even that's flimsy - they'd probably be asked a few questions, and politely told by detectives "we'll look into it" while the case gets buried.
Joshua Martinez attempted to defraud Chris of money and goods, which is more likely to have resulted in him being charged if the Chandlers pursued it. It was penny ante petty shit, so wouldn't have resulted in much, assuming he has an otherwise clean criminal record.
Bluespike attempted blackmail, but is a juvenile which may have resulted in a warning to minor charges. Adult trolls who might have been involved in the Julie saga could have had blackmail charges pinned to them, if there was any hint they were advising Bluespike.
Cyberbulling is still a huuuuge gray area, with very little prescience to suggest what might have happened. Chris being an adult (in the eye of the law), is a huge x-factor. It might result in most complaints being laughed at, and ignored.
I wonder if Chris' house or car have ever been vandalized, due to his internet infamy or general creepiness.
Bear in mind, I am not a lawyer, but I do drink a lot of vodka... Trust what I say implicitly.
The photos of Chris are generally considered legal, given that they were taken in a public place. Those taken in a business location are generally only restricted by the rules set by the business, and they may only bar you from the premises (though they may seek charges if those photos are released). The photos of his home and vehicle oughtta be legal, as long as they were taken from the street.