Satire and humor have limits
Though there are many uses for humor in activism, at every level, campaigns are way more important than jokes—or any individual action.
A single humorous action can help spread ideas far and wide—like when apartheid-era zombies communicated that nothing substantial has changed in Cape Town, or McDonald's offered free Happy Meals to victims of NYPD racial profiling, or (especially) when revolutionaries made regimes look like idiots with one wacky image or a series of jokes.
But "Stop and Frisk" was overturned by a sustained, coherent campaign, not just humor. Milosevic and Mubarak were toppled by mass action in which humor played a small role. And to really overcome the new apartheid of Cape Town, it's going to take more than some zombies running around.