Kirsty woke up to find that someone else had taken control of her Twitter account. I tell her how to get it back.
You have to fix this immediately. When someone else is sending out tweets and DMs under your name, you're in danger of losing your credibility.
The first thing you need to do is try to log onto Twitter. If you can do that, change your password. This will stop the Twitter thief in his or her tracks, and regain you control of your account--if the thief hasn't already changed the password and locked you out.
[Email your tech questions to firstname.lastname@example.org.]
If you can log onto Twitter in your browser, click the tool icon in the upper-right corner and select Settings. Click Password on the left pane, then enter your old and new passwords. And please, make your new password is a strong password.
If you can change the password, you have my permission to sigh with relief. But your work isn't over. Keep reading.
If you can't log on or change your password, you're going to have to go through Twitter's customer service and submit a Support request. See the service's own My account has been hacked page for details.
Once you've changed the password--either on your own or with Twitter's help--send out a tweet apologizing to your followers. Explain to them that those tweets weren't yours.
Then delete all of the tweets you didn't send.
Next, block all third-party apps from accessing your account. Click Apps on the Settings page's left panel. Click Revoke access for every application. You can reactivate them later.
As added protection, setup Login verification:
Now about those apps. Go back to the Apps section and click the Undo Revoke Access buttons for each app--or at least the ones you actually use.
Next, change your password for those apps--especially the ones on your tablet and phone. Unfortunately, thanks to login verification, this will be a bit more complicated than it used to be, and requires a PC handy: