I heard about someone cheating at a casino I played 2 weekly tournaments at. He would take chips off the table when he had a lot of chips and then bring them with him to the next tournament. I'm not sure how long he did this for as I heard it second hand but he did get caught. After one of these tournaments the tournament "director"(these tournaments weren't well ran) and the dealer from the final table counted the chips and they were 7k or 8k sort. They then told the dealers at the next tournament to pay attention and caught the guy putting chips on the table.
Now as for me seeing cheating at a live table. It's not exactly cheating but a very dirty angle. I was play 2/5 PLO. This was about 4 or 5 years ago so I don't remember the exact hands. Anyway I had QQ KJs or something similar. I started the hand with 3k. Couple of limpers short stack of around 120 pots it, i 3 bet button to 128, SB flats folds to short stack calls all in. Flop comes KJh rag. SB Checks, I bet 350, SB calls. Turn is an offsuit 9. SB checks again I bet 675,SB calls. River is small heart. This is were the angle comes SB immediately says pot, fml I go into the tank(not sure if one of the Q's was a heart but not really relevant) I know this guy plays a lot of PLO a a different casino(my regular casino had PLO once in a while so most players a holdem player and aren't that good at PLO). I was sitting in seat 3 and SB was in seat 4 and his stack wasn't visible to me as he was leaned forward resting one arm on the table and the other hand was on is cards. So after tanking for 4 minutes or so I end up folding. SB shows AhAs rag rag. Short stack mucks. After the guy moves his arms to rake in the pot(just before I was about to say nice
bluff) I see he only had 250 behind and I said are you ****ing kidding me, you say pot when you only have 250(which obviously I would have called) and he says oh I didn't know and then to make it worse his friend he came with says he doesn't understand PLO that well. So instead of go crazy and having a screaming match with him and his friend, I took 250 from my stack and went to the bar and drank for an hour to calm down.