Staring on September 27, any player that racks up three or more seasonal bans could get permanently banned from Overwatch’s Competitive Play. This means that if you are a dick to your fellow gamers, you could get perma banned.
Overwatch Community Manager Josh Engan said on the Blizzard forums..
“Seasonal bans do not need to be consecutive to qualify for a permanent Competitive Play ban. For example, if a player earned seasonal bans in seasons two and four, and then earns another ban in season seven, he or she will be eligible for a permanent ban from Competitive Play as soon as that third seasonal ban is issued.”
Engan also confirmed that once you are issued a permanent ban, it can never return.
Other types of violations such as being AFK or disconnection can result is a seasonal ban, but not a permanent ban once a certain number of times has occurred.