Login ID And Passwords Automatically Added To The Safari -> Preferences -> Passwords

[EDLIU]

My MacBook Pro(macOS High Sierra v.10.13.6) has automatically added User Names and Passwords that were not created nor added by me.

I have removed the unwanted User Names and Passwords, but am curious why and how this is happening.

Thanks.

 

[chabig]

...automatically added Login ID and Passwords...

Please clarify. I don't understand what you mean. Are you referring to user accounts on the machine that are not yours?

 

[EDLIU]

Safari -> Preferences -> AutoFill - User Names And Passwords

Has added User Names and Passwords that were not created by me.

Thanks.