It'll definitely be used for that. There are already state legislators scrabbling to find new and interesting ways to out queer and questioning kids to unsupportive guardians. I'd check up on whether any of these bills have been passed yet, but I don't feel like getting even more depressed today.
I'm sort of surprised that ISP's wouldn't give out search histories of minor kids to their parents. Maybe they don't want to be put in a position of arbiting family disputes, especially since there have been people who claimed to be concerned parents when they were actually something a lot creepier.
The police can just about always get an ISP to give them whatever data they want, which would be ok if actual police officers hadn't been known to pull some pretty creepy shit as well.
Thank God life is fairly brief and nonexistence is otherwise eternal. I wouldn't want to have to worry about this sort of crap forever.