You could lock them out of your containers first, literally. I can remember when player storage chests were locked by default.
Originally posted by neock: its sad how many people are normalizing this kind of thing. its a great annoyance that contributes NOTHING to the game aside from frustration. then again, funpolice- i mean facepunch seems to think cauing the community issues is the way a dev should be...

When people suggest workarounds I wouldn't construe it as endorsement. Of course it would be a better user experience if multiple people could interact with the same container at the same time. The devs know that too. But you're not going to hear "good idea, I'll get that implemented for the next release" because the people here don't work on the game. Even if a dev did visit here, they don't want to talk about contemplated features or in progress features until they're finished. So unless TFP have announced some change on this (which they haven't), all that's left to say really is yup I agree, no I disagree, or advice on how to make the best of the game as it exists.