Just install an NSA-B-GONE, my janky open-source modboard that adds Thinklight-controlled USB hardware switches to the webcam and microphone! Designed for the X220, but the X230 is pretty similar so I bet it would work: https://github.com/zakqwy/NSA-B-GONE

Of course, if everyone does that, attackers will just start pulsing Thinklights and seeing if anything enumerates, I suppose.