Response in such circumstances should always be driven by what you'd want other people to do to your property.
Did once share a flat where we had problems with someone leaving their bike in the corridor, rather than locked up with all the others in the basement.... my flat mate took the initiative to leave note on the bike the first and second time, then started letting both tyres down each time the bike appeared.... only took for him to do it twice before they got the message....
Response in such circumstances should always be driven by what you'd want other people to do to your property.
Did once share a flat where we had problems with someone leaving their bike in the corridor, rather than locked up with all the others in the basement.... my flat mate took the initiative to leave note on the bike the first and second time, then started letting both tyres down each time the bike appeared.... only took for him to do it twice before they got the message....