From chat

According to one story, Leon
said to have been particularly
fond of a Jewish dairy restaurant called 4
Triangle Dairy in the Bronx, whose waiters
were Russian emigrés. Trotsky refused to tip
after eating as a matter of principle, insisting 4
that "tipping was demeaning to the dignity of А
а workingman, and that a person should get a 4
regular salary, enough to live on, and not have
to depend on tips". For the same reason, he
tried to persuade other customers to refuse to
tip as well. This led to verbal abuse, poor
service, and one incident where waiters
intentionally spilled hot soup