That guy is called Michael Youn, he's a french comic/show man, that can be very funny but most of the time is just willingly stupid, he started out on TV with that show called Morning Live.
The megaphone sequence was a regular one in his show, when he always found new stupid things to do or places to go to shout through it.

In that one he starts off saying he's shocked that big police officers with big motorcycles "abuse" a small young guy with a small scooter, and that he's going to show them what his family car is made off. So basically he shouts:

"Aren't you ashamed of bashing on poor small defensless young guys? Why don't you go after real big crooks he? People of your own size and strength? Why don't you go after the Mooooorning Liiiiiive, from 7am to 9am, the show that wakes youuuuuuur Neiiiighbours!" and then tries to get away.

This one I'd never seen, it is pretty stupid and dangerous too.

Last thing this guy's done his a Jackass like movie that's in theatres in France right now.

Ponrauil