garbage cans, recycling bins, and chairs as parking spot reservation devices

[in_vino_vanitas]

I live in Allston, in a neighbourhood with no permit-only parking. I have recently noticed that people are taking to sticking random crap into curbside parking spaces with the intent to reserve them. I sympathize with people wanting to save a spot they shovelled out for themselves, but is this sort of thing common practise? Is it some fad that will pass once someone realizes allston christmas came early and they can get a full set of patio furniture just by cruising through the neighbourhood?

I've seen it before in other cities, snow or no snow, and people have interpreted it as both douchebaggery and fair use. What say you, b0st0n?