Unless you've been living under a J-blog rock, you've certainly heard about the story of the woman who was beaten up on a bus for refusing to sit in the back of the bus.
I don't know whether the story is true or not, nor do I have any way to verify it. However, it should be noted that the issue involved is only one of a chumra, a stringency, and certainly not one that is universally held. There was certainly no Rabbinic or Biblical commandment being disobeyed here.
And yet, could you see this story happening because she was eating treif on the bus? Could you see it happening because she was eating chometz on Pesach? Could you see it happening because she was returning from having been on the Temple Mount? Could you even see this happening because she had a tattoo?
Personally, I cannot. If someone were to tell me that she were beaten up for violating a mitzvah d'oreissa, I'd have a hard time believing it - but for this, it sadly sounds plausable.
Funny which "violations" will cause people to react violently.