Anti-skateboarder lumps for your precious concrete

Under the rallying cry, "What is deemed by skaters and bikers as 'creative expression' is costing you money," SkateStoppers sells bolt-on anti-skateboarding lumps that cause skaters trying to grind down your bench-edge, concrete shelf, or staircase to fall over and break their heads. The FAQ is full of dry stats about what happens to your marble floors when skaters abuse it, but no cool revenge-porn about the chaos these little babies sow among unsuspecting skaters. They remind me of the thin, anti-pigeon spikes you see on top of signs and ledges in train stations. Link
(via Beyond the Beyond)

Update: AV sez, "There's a constant battle between the skaters and the installers - they actually rent power equipment and grind the stuff off!"

They're not bluffing. Skateboarders routinely conduct guerrilla missions to remove what they call "Nazi knobs" from their favorite skate spots. They use saws and power tools, and sometimes cellular phones to connect the demolisher to the lookout.

"One dude cuts and one dude's watching and one dude is ready to run with the generator," said Rob Dyrdek, a professional skateboarder who admits to removing Skatestoppers. "It's pretty ridiculous."

Once, while Loarie was installing Skatestoppers at a school in Orange County, a young skateboarder walked up to say he'd be back to tear them out over the weekend. Later, Loarie said, the Skatestoppers had been hacked off and human feces smeared across the wall. Three weeks later, Loarie installed a new kind of Skatestopper with an experimental anchoring system.