trash fence

Trash fence: the furthest bounds of a social "safe space", beyond which you're back in the cruel cruel world.

Originally from the Burning Man festival. The trash fence is a pentagon-shaped temporary plastic fence nine miles in circumference, completely enclosing Black Rock City during the festival. Its purpose is primarily to catch windblown trash for later collection, to uphold the "leave no trace" ethic. It also marks the outermost boundary of Black Rock City; beyond that, you're on your own.

"Three dots will trip you all the way to the trash fence."