Manhole Cities battling theft of copper wire? Old news.

The big story now is about disappearing manhole covers. Take Philadelphia, as reported in the New York Times :

More than 2,500 covers and grates have disappeared in the past year, up from an annual average of about 100.

Thieves have so thoroughly stripped some neighborhoods on the city's north and southwest sides that some blocks look like slalom courses, dotted with orange cones to warn drivers and pedestrians of gaping holes, some nearly 30 feet deep.

The skyrocketing costs of iron and steel mean thieves can get a nice price for the purloined covers, from $5 up to $30 or $40, depending on the size. It's a problem plaguing cities across the country:

Phoenix has lost more than 160 of its manhole covers and street storm drains this year, up from 10 last year.

More than 80 drains and manhole covers have been stolen in Long Beach, Calif., this year and at least two local car owners who drove over the open chambers have filed claims against the city.

Starting last year, such thefts in Cleveland, Memphis, Miami and Milwaukee have more than doubled compared with other years, although New York reports no such increase.

Maybe cities should start making manhole covers out of something that's actually losing value. Like dollar bills.