Last Friday on my way to work on Brokaw just after going under 880 I ran across a box cutter razor blade that sliced my tire and tube. There were between 10 and 15 blades in the bike lane.They are the type of blades that comes from box cutters. I didn't see any box they could have come from like they fell off a truck. I'd be surprised if they had been put there deliberately but has anybody else had a similar experience? Maybe it was one of the 25 people who were given tickets on Brokaw and 1st on bike to work day for cutting into the bike lane? I picked up the blades before walking the rest of the way to work.