Psyringe: It's okay to publicly deface a family member if it's done in retaliation
orcishgamer: See, I consider myself fairly progressive, but I have a big problem with this. Kids don't get privacy (beyond performing basic grooming). They don't get a locking door or expectation that I will not find out what they're up to. So long as I'm legally and ethically responsible for them I reserve the right to snoop, spy, and do whatever else I must to find out what they're up to. Because no matter what kids think, or whoever else for that matter, kids sometimes get into shit that will seriously and forever fuck them up and I refuse to be one of those parents on the news, "But everything seemed just fine... *sob*". No, fuck that, kids don't get privacy from their parents, imo, and that video is a the perfect illustration of why.
(Side note: I think you were actually replying to a different sentence than the one you quote, i.e. the one about spying on the kid's facebook account.)
Regarding your reply: That's fair enough. Of all the points I listed, the "spying" is certainly the most acceptable one. Personally I'd be very reluctant to do it, but it depends on the kid and on the situation. Ideally, if there's an atmosphere of trust and honesty, then I don't see a need for maximal surveillance. Practically though, such an atmosphere may be difficult to achieve and maintain. And if I get the feeling that something bad might be going on, then I'd look around too ... though it's a gradual process, e.g. I'd need to be _very_ worried before I'd consider reading my kid's diary, but I wouldn't exclude it either. Spying on a facebook account is less problematic (since it's less private than a diary), but I still wouldn't do it without any indication to be worried.
But it's one of the (many) aspects of parenting where there are no clear-cut, context-independent rules or recommendations, imho.
However, regarding your kid, I have a hunch that (if she's got anything from you) she will be smart enough to find ways to privacy that you won't find out. ;) It just depends on how much effort she wants to put into finding such a way, and it of course gets easier the older she gets.