Either this is the start of some awesome Batman-esque samaritan vigilantism, or an absurdly elaborate scheme to take your wallet along with your bike. Our friend Alan Belsky spotted this on Court Street yesterday, and he says the signs are posted everywhere between Schermerhorn and Atlantic.
The sign reads:
“I RESCUED YOUR BIKE
I intervened a bike robbery in progress on Monday, June 25th. There were two bikes: one grey and one black. The robber was able to make off with the grey bike, but I was able to rescue the black bike with a stronger lock. If this is your bike, it is in good hands and I would love for you to have it back. Email me at firstname.lastname@example.org”