Recently WAMU had a short story on vacant and blighted properties. DC Council member Elissa Silverman wants to change the law to place the burden on the property owner. However the problem seemed to be that there aren't enough inspectors. There are only 4 for the whole city.
There are problems with switching it around to place the burden on the owner. Friends who bought and lived in a formerly vacant house, had to pay the vacant rate for at least a year (maybe more) taking out a loan to pay it while they tried to convince the city that they lived in their house. I wouldn't want to wish that nightmare on anyone. I get the desire to get vacant properties occupied but we should not trample innocents in our zeal to get at wrongdoers.