JUSTIN BIEBER learned a lesson at a recent concert.  If a fan throws her phone onstage . . . and you take pictures of yourself with it, and then hand it back to her . . . that isn't the only phone that will be thrown onstage lol. After Justin did that nice gesture for one fan all the girls were throwing their phones on stage..

His response was "Hey, no!  We're not just going to keep throwing cell phones up here, and expecting everyone to just get pictures of me.  No.  That's not how it works.  I'll never do that again, so don't even try it."