Steam Self Locking is a tool to lock your steam account, if your asking yourself why would I lock my account?
If you suspect your account has been hacked or something similar you can use the feature to lock your steam account for protection.
What does it do?
Once you activate it no one can buy games, trade or play any vac games and the community tools are closed too.
How do I Steam Self Lock?
Its very simple, when someone or you change something on your account like email steam guard you will get a notification email from steam about those changes and in that email is a link to lock your account.
When locket, please ensure that you write down the provided unlock code. Once the account has been secured, this code can be used to remove the restrictions.
You cant lock your steam without a notification email, there is no tool or option to use it only when certain changes are applied to your account you can activate Steam Self Lock.