Check out this standpipe. Above it, there is a fire escape which has obviously-painted-over graffiti. On it, there is a mess of thick, black grease, and next to it is a coil of razor and barbed wire.
Hadn’t seen this rather extreme approach to climbers before.
Near my building there are often streetwalkers. They tear the rearview mirrors from vehicles, presumably to check makeup/freshen up. After several losses, one of my neighbors applied axle grease to the back of his mirrors. The interesting thing, in my mind, is that it’s not the slipperiness, it’s about and cleanliness and appearance. For someone who lives on the street, a sink and special soap for heavy grease is hard to find. For a community that is visually oriented and fashion conscious like graf artists, something that spoils a new set of Converse may be a better defense than something that threatens life and limb.