San Francisco 49er WR Kyle Williams was on the wrong side of Lady Luck on Sunday when his costly overtime fumble led to the game-winning Field Goal for the NY Giants. Of course, it’s ridiculous to rest an entire game on one play, but it’s natural to assign blame to the last huge error that leads to any loss.

But after what must have been a terrible night, Kyle Williams is seeing the nasty side of social media as some 49er fans have taken to Twitter to send him nasty messages and even some threats of physical violence.

Check out some of the tweets:

@javpasquel
JAVIER PASQUEL@KyleWilliams_10. I hope you, youre wife, kids and family die, you deserve it 14 hours ago via Twitter for BlackBerry® · powered by @socialditto

Many of the threats have been deleted – probably a smart idea.

Athletes (and any public figures, really) have to navigate Twitter and other social media carefully – from both sides. We’ve seen plenty of instances of athletes getting in trouble for controversial tweets, but that’s not all they must worry about. Twitter is an open service that allows public access to your account. And people can be vicious, especially when protected by the certain level of anonymity and lack of interaction that Twitter provides.

And of course, sports fans are simply f*cking crazy sometimes.

But if you want to restore your faith in humanity, just a little bit, check out tweet directed @ Kyle Williams in the past hour or so. Once news of the unsavory tweets began to break, users flooded his account with positive messages.

I’m just happy for Billy Cundiff that he’s not on Twitter.