Who does stuff like this?

Via NY Post:

The letter addressed to Donald Trump Jr. that contained a suspicious white powder and landed his wife in the hospital Monday said, “You’re an awful person and now you get what you deserve,” according to law enforcement sources Tuesday.

The note was delivered to the Upper East Side home of Trump Jr.’s mother-in-law around 10 a.m. Monday, sources have said.

The wife of the president’s son, Vanessa Trump, opened the letter and discovered the powdery substance and note, sources said.

Realizing the potential danger, a panicked Vanessa Trump then ran out of the room and stashed the letter and powder in a plastic bag and called 911, sources said.

She was rushed to the hospital as a precaution.

The substance turned out to be cornstarch.