lol boy did I miss the mark. Sorry I must have misread
I'm not sure of any way to lock it, especially if it is an admin doing it (which it must be right?). If someone has read-write access, there isn't a way to stop it.
What you can do is setup email alerting for when changes are made to a network and you can see who is doing it that way.
You can also go to ORG>CHANGE LOG and from there you should be able to see who and when if any changes were made. I say 'if any' in the off-chance its being done because of a bug and not another admin.