I rarely have any problems. Make notes. I have called 1. The DAD, who was unhappy. Apology call was prompt. 2. The BOSS who wasn't happy.
And have simply ignored idiots. They've got the problem, not me. Eventually it will catch up.
Can you really defend yourself? I know cyclists whose past includes special warfare, boxing, etc. None of these folks pays any attention really. If someone really wants to pick a fight, a pumped up cyclist is the wrong person to pick it with in general terms.
Calling an authority person works much better.
Of course, in cities where everyone is a stranger might make that hard. I try to avoid cities. Here I can figure out who is who pretty quickly. Now if White Ford F150 and Cell Phone Escalade ***** would only commit fratricide and take Yukon Idiot and Town and Country What's A Stop Sign with them . . . . That would be a treat! I know where they live, but they're not worth talking to yet.
"Excuse me, but it's inappropriate and possibly illegal to swerve at me and yell."
"watcha gonna youmtufacter - me n my buddies gonna whip yoass."
Now, is that the scene you want? More difficult than you'd think to out accelerate hopped up teens on foot.
Let it be.