Can you support that? History is filled with protests leading to change. Just looking at 100 years off the top of my head: Women's vote, Gandhi, civil rights, S. Korea, the fall of the Soviet Block, the Arab Spring ...
In France, countless pictures of pallets of bricks being delivered to demonstration sites in the night before the protest opposed to the leading party, in addition to criminals not being arrested, should at least give you a doubt on how much the “bad vs good” show is artificial.
Many legitimate protests from people who actually are minorities in their nations, were put in bad light and you never heard of them.
It's an attempted tactic, though in the US I think by the political opposition (radical neo-reactionaries) and not the government. It has uneven success.
> countless pictures of pallets of bricks being delivered to demonstration sites in the night before the protest opposed to the leading party
Do we know those pictures were legitimate? Countless pictures on the Internet doesn't mean much.
> Many legitimate protests from people who actually are minorities in their nations, were put in bad light and you never heard of them.
How do you know?