Cyclists all know that SF has a bike theft problem. And even when cyclists use expensive u-locks, those can quickly be cut with angle grinders — a fact which many know all too well. Faced with this distressing reality, a local engineer came up with a unique solution: a "bike lock that Fights Back." Say hello to the Skunk Lock, a u-lock that has a pressurized vomit-inducing liquid inside that, if cut, sprays all over a would-be thief.

"After my friends and I had our bikes stolen over and over we decided to revisit how a lock could deter a thief and start a revolution in the process," inventor Daniel Idzkowski explains on the lock's Indiegogo page. What they came up is a lock that's "pressurized inside with a noxious chemical deterrent that slams the would-be thief with noxious chemicals."

Idzkowski went into more detail in conversation with The Guardian, noting that the payload is delivered after about 30 percent of the lock is cut through "It’s pretty much immediately vomit inducing, causes difficulty breathing. A lot of similar symptoms to pepper spray.”

He says the chemical is legal, and that he has tested it on himself and friends (with permission, one assumes). “At two feet it was pretty bad," he told the paper. "It was absolutely vomit inducing in 99% of people. At five feet it’s very noticeable and the initial reaction is to move away from it."

Idzkowski hopes to deliver the locks by June of next year, and his Indigogo campaign is over halfway funded.

Related: Video: Today Show Chases Bike Thief In San Francisco