There are a number of stages with regard to bans. Egregious violence can result in an immediate ban. An egregious breaking of our rules like posting child sexual exploitation material can result in an immediate ban.
To be honest, most users who receive an action have made an error, and in our asking them to take that tweet down, they will apologize to their users once they have received that kind of information. We are looking to hopefully provide avenues for corrective behaviour, for counter-speech, for others to come and run to those conversations, and talk about different issues, or ask people to behave differently.
There are a number of measures we use. We can action a single tweet. We can lock down an account, but to ban somebody from Twitter completely is a very big deal for us that we take extremely seriously.