This one will be a lesson in not blithely agreeing to bug fixes for "this build" just on the basis of how much I don't like the bug.
It required updating how I handle saving... considerably, but this is done... boy is it ever done. Thanks for the report!
For the record, I'm probably not doing much more on the "local security" front until I'm out of alpha though.
People who are determined to muck with things will be able to muck with things no matter how much time I spend on it, and I'm not interested in spending time on an arms race I'm unlikely to win anyway, especially not while the player base numbers in the dozens.
I do agree it shouldn't be as easy as just closing the window though.