Under the 'Stupid, stupid STUPID!' label,

A group of deaf friends were stabbed at a bar in Florida after a woman mistook their sign language for gang signs.
...
The 45-year-old though the group was throwing gang signs at her, and responded by flashing gang signs back at them, cops said.

The group motioned for her to leave them alone.

Eventually, left the bar but returned with two members of her crew, 19-year-old and a 17-year-old who was not identified, cops said.
Yes, I removed the names, as it'd probably make these wastes of oxygen happy to have theirnames paraded around.
Ibanez allegedly pulled a knife and began stabbing Stewart and his friends.