The recent League of Legends World Championship had quite a bit of drama involved, with network connection issues being the least of Riot's problems. Allegations of cheating (basically, screen looking) encouraged Riot to investigate and after a full review of each questionable match, have made their decision. Although initially Riot seemingly innocently announced that nobody had looked at the minimap, people found evidence that was to the contrary when looking through recorded streams.
So Riot conducted an investigation and weighed the evidence of cheating against its impact on the match and cleared one team of misconduct, issued warnings for "un-sportsman like conduct" to three others and fined team Azubu Frost 20% of its winnings (or $30,000.) The fine will be donated to Riot Games' charity program in Korea. Many are not satisfied however, as the teams—even when guilty—all got to keep the rest of their $150,000 dollar prize. Others pile the blame on Riot for even having the ability to look at your opponent’s screen, something that Riot does take responsibility for.
Hopefully for Riot Games their future tournaments will go much more smoothly from what they have learned from this one.
Source: Riot