Why do we need streetsweepers?

FUNNIEST thing ever (okay, not even close, but still, pretty darn ridiculous): watching this giant, cold war tank machine the size of a trash-compacted house slowly and noisily lumber up our street to turn, dumbly, in a circle in our sidewalk - slow and imperious, deliberate and dull and unstoppable - wondering what the heck it was doing only to see it has little tiny brooms uselessly shuffling along its side.

HA HA! WHat the heck?? So much structure, gasoline, energy, and seriousness for an automated and pointless BROOM??

Seriously -- how much money does it cost to run these machines, and shouldn't it be going somewhere else? There's plenty of litter in the city that will not be reached by these ineffectual little sweepers... not to mention homeless people and all that.

Good god, it was ridiculous.