If they are naïve, gullible, and easily trusting, this is not a good game for them. If your child is mature and knowledgeable enough to not fall for predatory tricks, generic bullying, and overall rude language, they'll be fine. However, ultimately, this is not a game for naïve children. There are some security issues, but they aren't as bad as they were years ago. There are some bugs, but they aren't really game-breaking, most are pretty funny.
What I like about this game are the people I've made friends with, and of course the visuals.