The fact that these left wing lunatics are even down there harassing both the owner and the patron just indicates how misinformed and misaligned their thought process is.
Why there ? What's their point ? Why wouldn't these brain dead hippies protest any restaurant that serves any type of meat, it's all the same.
They have clearly singled him out and began a campaign of harassment and ostracising one person repeatedly based on their personal opinion and anger. They stand out front and watch with the intent to intimidate the owner.
That is clearly Criminal Harassment.
These people should be removed from the front of the premises by the police, warned once then arrested.