Its true you know, crew belongings go missing all the time. A friend of mine had her handbag swiped once (her work one so it would have been hard to deny it by a pax) and she only noticed as she went to get it as she was disembarking. Lone behold the passenger who swiped it was making a transit stop and didnt realise that to get airside he would need to go through another x-ray machine, they caught him there and she was reunited with her bag!!!
I personally lock my laptop if I take it with me on trips into either the crew rest area or the diplomatic lockers. That way if it does go missing I can narrow it down to the crew or that off duty crew!!! lol