Well, yeah. Most laws are there for a reason. I don't think it's moral to blindly follow the law, but it is moral to understand why the laws are in place and then choose to follow them.
Personally, though, I think that if a particular action doesn't affect anyone negatively and doesn't involve anyone who's not directly involved, it's none of my business, legal or not. "There's no place for the state in the bedrooms of the nation", for example. The legality of whatever people do in their private time, so long as it stays private, doesn't really matter. Since it's private, no one besides them knows about it, anyway. 'Course, there's an important caveat to this: this only applies if someone involved is not being harmed. Abuse, for example, is a problem whether it's private or not.
Personally, though, I think that if a particular action doesn't affect anyone negatively and doesn't involve anyone who's not directly involved, it's none of my business, legal or not. "There's no place for the state in the bedrooms of the nation", for example. The legality of whatever people do in their private time, so long as it stays private, doesn't really matter. Since it's private, no one besides them knows about it, anyway. 'Course, there's an important caveat to this: this only applies if someone involved is not being harmed. Abuse, for example, is a problem whether it's private or not.