Bind account with mobile number to prevent people from creating multiple accounts
Right now people can create several accounts with just a new e-mail address (or delete an old account and create a new one). People that are harassing streamers usually does this, and it's unacceptable.
Twitch needs to do something about this, because it's gone too far. Bind accounts with a mobile number and let the owner change his/her name Once, because the name we chose 2 years ago might not be suitable today.
When a user register a new account on Twitch, they need to verify their identity with their phone number (for example sending a code via SMS that they need to enter to verify). And of course people can't just delete their account and create another one with the same number, it's locked to that specific username.
This will drastically reduce the harassment and bullying on Twitch.
The inability to limit account creation and spam is the price of existing on the internet. It's just the way things work. It isn't much more difficult to create infinite phone numbers that can be checked for SMS than it is to generate infinite email addresses. There are literally free services where you can get a phone number in any state in the country and use it for SMS authentication. Preventing multiple accounts for one phone number would negatively impact people who have reasonable purposes for doing so while not actually preventing untoward people from doing anything.
Its Invis commented
Phone verification does sound like a good option.