Algorithm to detect passwords that contain personal information:

1. Gather information about the user such as their name, date of birth, address, phone number, etc.
2. Create a list of potential passwords that contain personal information.
3. Analyze each candidate password against the gathered personal information.
4. If a candidate password contains any of the user's personal information, flag it and return an alert. 
5. Else, return the candidate password as valid.
Create an algorithm to detect passwords that contain personal information.