The biker thugs had a camera turned on because they planned to do this. The thug made sure this happened.
The thugs initiated this
Yes. I have trouble understanding what WayneS wrote.
They all have helmet-cams so they can record themselves doing dangerous stunts, evading po-po, creating pubilc nuisance, etc.
They record each other, then upload it to youtube and Facebook where they can impress each other with how stupid they are willing to be.
Harassing motorists is par for the course for these streetbike-gangs.
They do it for entertainment.