It's National Bullying Prevention Month and as much as the pros on tour seem indestructible, they're as susceptible as anyone else to online bullying. Players have been hounded online after both wins and losses by rude commentators, better known as "keyboard warriors".

It's been a fast-spreading and seemingly unstoppable epidemic, but some players are standing up to the haters. Stars like Madison Keys, Nick Kyrgios, Nicole Gibbs, Dustin Brown, and many, many more have fought back in their own ways.

Brown just lost a tough third-set tiebreaker at an ATP Challenger in Italy and had this to say:

If 1 Of U #KeyboardWarriors Would Actually Say These Things 2 My Face After A Match, Id Def Know Where Id Break My Racket... pic.twitter.com/BzuOYGFPgs — Dustin Brown (@DreddyTennis) October 12, 2017

It's not just the players who are fighting back. Pat Cash, the current coach of CoCo Vandeweghe, was impressed by Kyrgios' essay in Australia's Players Voice.

Read this honest and moving post by @NickKyrgios. Great read and a worthy project. Nick let me know how I can help. https://t.co/qlRLcwyEWO — Pat Cash (@TheRealPatCash) October 9, 2017

The online trolls are always quick to rag on Kyrgios, but Cash was having none of it:

You don't know what you're talking about @BongomanJungle. Completely missed the point.Please unfollow me & take your trolling somewhere else — Pat Cash (@TheRealPatCash) October 9, 2017

I don't have patience for name calling or aggressive negativity in real life and won't engage with it on Twitter. — Pat Cash (@TheRealPatCash) October 10, 2017

Polite disagreement and criticism is fine. Non constructive impolite comments from whiny trolls = block/mute from me. — Pat Cash (@TheRealPatCash) October 10, 2017

Please take your negativity elsewhere @ttimbertony — Pat Cash (@TheRealPatCash) October 12, 2017

It seems like an insurmountable obstacle, but these voices are doing their part to stand up for themselves, and for all of the players.