There was a debate over semantics elsewhere that fits in with this.
Is it (or should it be) "I could care less" or "I couldn't care less"?
"I couldn't care less" seems like it hits harder, and I admit I'm more likely to use it or a derivative of it over the latter, but it must be pointed out that one who has opted to use this phrase surely cares enough to remark, so one could care less and simply not remark.
That's funny.
Obviously it's "I couldn't care less". Because you're exaggerating (clearly) about how little you care. If you say "I could care less", you're actually saying that you care. Which is not usually the sentiment one wishes to express with this phrase. Yes I agree that it's not technically accurate, but it is an exaggeration.
"Nobody cares about your protest" is obviously also an exaggeration. I mean, clearly the other people protesting, and rioting, care a great deal about it. There's no question that BLM was a widely cared-about protest, and so there's about zero chance that the bumper sticker is meant to be taken literally. I think what it's really saying is "
I don't care (much) about your protest". But the sticker itself undercuts this message since it takes a decent amount of work to put on a bumper sticker. It would take even more caring to actually run over protesters and risk life in prison or execution for mass-murder.
I think the mistake in this case was to conflate "I don't care" with "I don't like". Not the same thing.
Edit:
I'd give the driver of this car about an 85% chance of saying that they're in favor of law and order while advocating, on the back of their car, in favor of real violent crimes committed against people exercising their first amendment rights.
Edit 2:
There's a deeper level to take this. Which would be that "nobody cares" actually means "nobody in my circle of friends and family, and if you're not in my circle of friends and family, you don't exist to me".