At least six readers have by now sent me the following photo, which was taken in Israel a couple nights ago during the historic street protests against Netanyahu’s attempted putsch:

(Update: The photo was also featured on Gil Kalai’s blog, and was credited there to Alon Rosen.)

This is surely the first time that “P=NP” has emerged as a viral rallying cry for the preservation of liberal democracy, even to whatever limited extent it has.

But what was the graffiti artist’s intended meaning? A few possibilities:

1. The government has flouted so many rules of Israel’s social compact that our side needs to flout the rules too: shut down the universities, shut down the airport, block the roads, even assert that P=NP (!).
2. As a protest movement up against overwhelming odds, we need to shoot for the possibly-impossible, like solving 3SAT in polynomial time.
3. A shibboleth for scientific literate people following the news: “Israel is full of sane people who know what ‘P=NP’ means as you know what it means, are amused by its use as political graffiti as you’d be amused by it, and oppose Netanyahu’s putsch for the same reasons you’d oppose it.”
4. No meaning, the artist was just amusing himself or herself.
5. The artist reads Shtetl-Optimized and wanted effectively to force me to feature his or her work here.

Anyway, if the artist becomes aware of this post, he or she is warmly welcomed to clear things up for us.

And when this fight resumes after Passover, may those standing up for the checks and balances of a liberal-democratic society achieve … err … satisfaction, however exponentially unlikely it seems.