Years ago I was friend with a guy who played tennis at international levels (say top 1000 players). He regularly received death treats on social networks from people Gambling on him to win/lose (and the opposite happened)

Getting death threats from aggrieved gamblers, MLB players starting to fear for their safety

https://www.usatoday.com/story/sports/mlb/columnist/bob-nigh...

Doesn't help when some MLB players also apparently participate in the gambling outcomes, too.

https://www.espn.com/mlb/story/_/id/46906636/guardians-emman...

Still happens at all levels of professional sport. Even the top women get messages on their IG accounts all the time by degenerate gamblers pissed off after a loss.