Paved paths are divided by a painted yellow line. Bicycles are supposed to stay on one side and pedestrians are supposed to be on the other. Both seem to be equally guilty of violating this rule. That said, I don't see much of a problem if there are very few people using the path at the time. People should just use common sense and have some consideration. Where have I heard that before?
Some other things I see adult cyclists doing and I'm only going to mention adults because they definitely should know better, are riding through crosswalks into traffic without even stopping momentarily. They shouldn't be using the crosswalk at if they aren't going to walk their bike across. When they are riding on the street, many of them ride right through stop signs and red lights.
Then there are the ones who insist on riding on the street in the wrong direction. Hey cyclists, when you're riding on a street, the law requires you to ride in the same direction as traffic as you are considered to be a vehicle. If you were riding a motorized bike or motorcycle would you ride facing traffic? I would hope not. The idea of facing traffic is only for pedestrians walking on the roadway.
If there is a perfectly good bicycle path along side a roadway then use the bicycle path, instead of insisting on hogging an entire lane of traffic on a busy street.