It can also be difficult to delete the accounts on some services. Sometimes [overwriting data](account-deletion.md#overwriting-account-information) associated with an account can be possible, but in other cases the service will keep an entire history of changes to the account.
## Terms of Service & Privacy Policy
服務條款是您在使用服務時同意遵守的規則。 With larger services these rules are often enforced by automated systems. Sometimes these automated systems can make mistakes. 例如,您可能會因為使用 VPN 或 VOIP 號碼而被禁止或鎖定某些服務的帳戶。 對這種禁令提出上訴通常很困難,而且通常都由系統自動處理而不是人工審核,造成了上訴的困難度。 這也是我們不建議使用 Gmail 作為電子郵件的原因之一。 電子郵件對於訪問您可能註冊的其他服務至關重要。
When you choose single sign-on in a website, it will prompt your SSO provider login page and after that your account will be connected. Your password won't be shared but some basic information will (you can review it during the login request). This process is needed every time you want to log in to the same account.