Smoke alarm and CO alarm, I provide.  

Invasion of privacy, unclean and rude house members, maybe if they do drugs or smoke or are party animals, unwanted friends of theirs visiting at odd hours, clashes of personality

Maybe there is a silver lining.

Total still owed $13,600 (rent, late fees, legal fees) and $550 for the locksmith.Place reeks of pot, she had her adult son, who by the paystubs left behind only made $152 a month and spent his days laying on the couch (which reeked of pot) smoking and playing x-box (abandoned and power supply cut up). 

Smoke and carbon monoxoide detectors & fire extinguisher. 

But seems to be a bit of a smoke screen. 

A smoke detector in every bedroom and a smoke detector and carbon monitor in hallway of every floor and in the basement or attic IF you have furnace, hot water heater etc in them.

Do we really want the government to rely on getting more people to smoke more marijuana in order to do their job protecting us and maintaining our infrastructure and schools?

Smoking is definitely happening in a unit (leased rental unit, inherited tenants).  

Lol someone says they're not interested in jumping through hoops means they're not serious or their buyer is all smoke no fire.