What will you do when somebody used your personal mug/cup without your consent

If somebody use my mug without permission then I would rather give it to him/her and tell that don't ever do it again, in that way he/she will be ashamed to used other mugs again.

i have one certain cup i use for drinking out of.it dont bother me at all if someone uses it or if they dont wash it after use.i do dishes anyway

you just tell him that he should know the meaning of respect, respect for the possessions of others, its about asking permission to borrow and wash it after used. but for me i will not let anybody to borrow my personal use, what if he has this illnessess that might tranfer to you? the right to privacy is an important value to acquire. it affirms crucial self confidence and worth. violations of privacy should receive the same consistent discipline as dishonesty and theft. you explain to him that stealing peoples privacy is the same as stealing their Goods.

You cannot change someones nature. If it is done regularly and you are so pissed off about it you can tell the person to do it again if you know who did it otherwise send a mail to all the staff in your office about this regular incident and tell that you dont have objection if someone uses the mug but atleast have a coutsey to wash it as per pentry instructions. If both of these doesnt works for you then better keep your mug in your custody. I will prefer to do either of these 3 options which I gave to you.