"Rampant cheating" means a widespread or uncontrollable occurrence of dishonest behavior, where many people are cheating or being dishonest in various situations. Full definition
Lastly, there is also the issue of rampant cheating on PUBG, leading to an exodus of players as Chinese hackers have invaded the game. (techtimes.com)
The Steam Community post by PUBG Corp. announcing the BP compensation is nearing 5,000 comments at the time of writing, but most of them are raising the issue of rampant cheating in the multiplayer shooter. (techtimes.com)
I can understand the need for some updates to combat rampant cheating — like Halo 2 had before the first update. (andymerrill.com)