Litespud

1) - yes, sort of. Outside Boston MA, passenger in a passing car threw an unopened soda can at me. Hit me on the back, but startling more than anything. The driver of a following car took their tag# and flagged me down at the next intersection to give me the #. I passed it on the cops, but nothing came of it
2) Only thing I've ever been in a position to respond to are dogs, and I either outrun them or head straight for them and yell really loudly. This usually throws them back on their heels long enough for me to outdistance them.
3) Avoid - there are endless places to ride a bike. I ride on the road exclusively, so while it's not ideal, I don't have to worry about pedestrians etc messing with me. Nothing would persuade me to ride regularly on an MUP.

I'm assuming that this is more of the same thread that recently went off the rails and was shut down. If nothing has changed since then, you had a pretty unpleasant run-in with three teens on bikes. I don't know if you've been back there. If you haven't, then this might have been a once-off, but the little feckers are clearly in your head, and the only way to get them out is to go back and see if they're there again. If they're not there, then chalk it up to bad luck and get back to riding. If you have been back and they were there again, then it looks like they've figured out your routine, and now you're sport to them. As I see it, your options now are either (i) find another route or time, or (ii) film an incident and take it to the cops. If they won't do anything, then confirm that you're on solid legal ground for carrying and using Mace or equivalent. Film the next encounter, wait until they have clearly committed some form of harassment or assault, then blast them. My concern is that it could go two ways - they might have learned a valuable lesson and stop screwing with people, or they might escalate. Maybe find another route in any case. Whatever you do at this point, don't bring a gun. If you draw it, you'd better be prepared to fire it, and remember that, at this point, these are presumably unarmed teens - little feckers certainly, but unarmed - and doing something irrevocable will bring a life-changing ton of crap down on your head