Question : Same user gets locked out at random

I have a user that seems to get locked out at random. They can go a week or two and only get locked out once or get locked out a couple of times in a week. Not sure what to check to get to the bottom of this. Any Ideas?

Answer : Same user gets locked out at random

Take a look in the Security log in eventvwr on each of your DCs.
This normally occurs because the user account is being used for an application, or service where a built-in account should be used, such as Local System.

Alternatively - this could just be someone trying to login to the user's account when not authorised to.