Why did ubunta start up without a password?

Question

ubuntu

Ubuntu began to run bypassing the lock screen (without requiring you to enter a password). I looked in the settings of the ultrasound - there was a check mark "automatic entry". At the same time, the password from the UZ was the same.
This is the only account, it is possible to execute commands through sudo, but I use this in exceptional cases. I myself did not put such a checkmark, someone else did not use the computer. Services sticking out (ssh, ftp...) - no.
Why could this happen?

Answer 1

You yourself initiated the automatic login flag change.
In other ways - it is impossible to do this without having access to a local account.

Answer 2

There was a checkmark "automatic login" and it is enabled.
at my house, ubunta also enters the user without a password - it's more convenient for a home computer.
I did this on purpose, according to some instructions.
look for instructions on disabling autologin.