I got this information from others, when I asked about sailing out of SJ in general.... it sounds like, on the 10-day summer sailings, the teen behavior becomes a problem. They explanation is that, given the length, the teens get bored, they get emboldened, and they link up in groups and that mentality takes over. They roam the ship doing mischief. There are reports of thefts, stealing, and even fights. How often this happens on any given sailing is not really known. Also, apparently the parents check out and stop parenting (although that seems to be happening everywhere anyway).
For me, if I was going to do a sailing where this might happen, I'd just prepare myself...decide if I will say something directly, or report it (security will get involved). Decide how much it would bother me. And I'd be careful where my stateroom was (not near the teen clubs and try to be out of the way, like very forward or aft). I probably would not display some of my more special magnets, and I'd be more careful with leaving personal belongings around while going to the restroom or whatever.