You might have old accounts especially cloud accounts that are just idling abandoned while still holding personal information. They might have old weak passwords just waiting to get compromised. Same goes for old email addresses that you do not use anymore but are still linked to other accounts. This is a reminder to check those, delete your data from them or to delete them altogether (delete private information manually first before deleting the account as many companies do not actually delete the data from deleted accounts and just mark the account as deleted).
Some examples of this could be:
- old Google accounts from old devices
- old iCloud accounts
- old Microsoft accounts
- old Aol or similar email accounts
- old accounts from smartphone vendors like Samsung, Huawei etc. that often have their own cloud services
Make sure to set a strong passwords on accounts you want to keep and of course use a password manager. Besides the security password managers have the great side effect of giving you an overview over all your accounts so that you cannot just forget old ones.