Manhole

WLWT Reports that people are stealing manhole covers. Well, actually sewer grates, but they posted this picture of a manhole cover.
The story says they cost $120 but the damage to you, your car, bike or segway, if you hit the hole, could be much more costly.
So, to get some revenue, maybe the city could sell miniature replicas of their manhole covers to use as trivets. Meanwhile, start using covers & sewer grates made out of something other than metal, like fiberglass. That is, generate a new revenue stream & curb losses.