Troubleshooting guide
I think someone is using my account
First, protect your access and sessions, then report suspicious actions without sharing any secrets.
Secure your login method
If you use a Dialova password and can log in, change it from Settings → My account. If you've lost access, use Forgot password. A new password should be unique to this account.
If you log in with Google, also secure your Google account through its service: a Dialova password change doesn't replace this step. Never enter your Google password in a message or support form.
Check sessions and the IRC key
Check Settings → Web sessions and close any sessions you don't recognize. If an IRC connection key has been shared, revoke it or replace it in Settings → Chat, Connection from IRC software. A simple avatar or nickname change isn't enough to protect your access.
Don't attach the key to a screenshot when explaining the problem. Also, check the security of your email inbox, as it's involved in recovery processes.
Add protection and alert the team
You can activate two-factor authentication in Settings → Security and keep its backup codes safe. Do this after regaining control of your access.
If messages or changes aren't coming from you, contact the team with the dates and actions observed. They can examine the situation; don't promise other members an automatic cancellation of all exchanges.