I registered a few years ago and I used the account sometimes. tonight I received an email from bitcoin talk forum that warned me that my email had been changed. I realized this morning that someone used my account to write some messages this night. How can I block everything? This person who changed my email setting used my account only this night. All the other posts are mine.
If you're the real owner of that account you must been sent link to lock your account,it look like this 'If you did not do this, then you can visit the following link within 14 days in order to lock the account:'