Log on to Twitter, Agree to New Policies, or Lose the Account

[engine]

If you've not logged in to your twitter account for six months you could lose your account after December 11.

Twitter is sending out e-mails to prompt people to log in, or lose the account under the inactive accounts policy.

To keep your account active, be sure to log in and Tweet at least every 6 months. Accounts may be permanently removed due to prolonged inactivity.

[help.twitter.com...]

[engine]

Update.
Twitter postpones this account deletion action. It says it didn't have suitable proceedures in place for "memorialising" dead users.

It goes on to say it will restart the action in the EU in due course when its established a process fo memorialisation.
[mobile.twitter.com...]