You can't expect Binance to not follow government regulations. It doesn't look like these cases are related to "tainted Bitcoins", it looks like they were flagged for other reasons. Nigerian scammers have quite a reputation on the internet, and your link shows many of them were blocked at the request of international law enforcement.
As I put it earlier:
Note that this isn't about exchanges freezing funds owned by drug dealers, that's understandable. It's about freezing funds from the bar where the drug dealer bought his coffee.
In this case, I don't think it's hte bar owner who got his account frozen.