Two players from the Quakelive clan Poland US got caught in an embarrassing story of cheating and aliasing yesterday:
Couple of days ago, the ESL PL Weekend Cup Series #16 has finished. Poland [US]Festival won in final game against me, Poland CEFO|bloodpa1nt, 18-8 @ ztn and 29-4 @ dm6. I never did so bad in an official game, especially on dm6 against someone with Festival's skill. I found that weird and talked with id Software's admins about it. It turned out that Festival used wallhack and got all his 7 accounts banned. Festival was convinced to use wallhack, but he said he only used it twice in some practice game, he also claimed he never cheated in ESL games.

A few hours later, I spoke to Poland [US]Blanka. Blanka said that he knows "something" about that final game in ESL WCS between Festival and I, but it wasn't easy to get that info off him. Blanka asked me to play ztn and dm6 and then we might speak about WCS once again. Blanka won ztn but lost dm6 twice, then he asked me on IRC "why didn't you play just like that in the final game?" and I answered "so it was you?" Blanka said "yes". Then Blanka invited me to a private channel with only Festival, Blanka and bloodpa1nt on it and Festival tried to make sure this info doesn't go public. Too bad.

Festival was an ESL admin and the founder of EQLT. Now he's banned from ESL for 2 years and there is no official info if he will keep EQLT cups coming up.

Sources: first and second news on cybersport.pl, Article on esports.pl. I also attached the proofs (they are polish though, but doesn't matter what language - it proves them to cheat).