Originally Posted by
StanSimmons
A Brooklynite cursing? How could that be dangerous, or even unusual?
A lot of them use curse words as adjectives on a regular basis.
The word "dangerous" or "danger" did not appear anywhere in the article linked by the OP.
It's just a matter of faulty assumption that the passenger was removed because he posed a danger. Atlantic Southeast Airline being a privately owned company, they can choose to deny boarding to anyone they don't want to carry.
If the CEO of the airline just decided he didn't want any passengers who use the F-word in earshot of his employee - the airline can make it a policy to deplane any passenger who utters the F-word.