[jiqiren]

Burden is on you to simply login. That’s all twitter is asking - login to show you still want the username.

[Cthulhu_]

And agree to their new terms and conditions - THAT is the real reason why they're doing this. I'm sure the new T&C's grant Twitter the right to do more with existing accounts / tweets.

[snowwrestler]

I think it’s far more likely that requiring human agreement to the new T&Cs is a convenient excuse to cull a ton of bots.