The Daily Show has been on vacation since Occupy Wall Street broke big in the media, so last night’s show was their chance to play catch-up. And they made some … well … odd choices.

Stewart led off the four-minute segment by calling OWS “the Hard Rock Cafe of leftist movements” before doing a gag about OWS’s fundraising prowess and another snarking on Mitt Romney’s opportunism. But the segment’s last — and longest — bit was this one:

“Of course it hasn’t been all good news for the movement. For all their popularity, for all the participants with thoughtful critiques of our power structure, there’s also this: A guy taking a shit [bleeped] on a police car.

“You know what? Guy shitting [bleeped] on a police car? Meet me at camera three.

“NO! NO! BAD! [mimes spraying with water bottle, whacking with rolled up newspaper] NO! NAUGHTY! NAUGHTY!

” ‘Cause here’s the problem. Unfortunately, protests are often as much about optics as they are about substance. And you do not want this [photoshopped photo of Chinese democracy protester shitting on row of tanks] to be your Tiananmen Square. You have tapped into a real injustice that people feel about the global financial markets. Nothing can derail your movement faster than someone who is unable to derail their movements.”

Now, I get it. It’s hard to resist a poop joke. I get that.

But here’s the thing.

In a grassroots movement like this, individual people are going to do stupid things on occasion. It’s unfortunate, but there’s no way to stop it. And as long as everyone recognizes that fact, and is attentive to the distinction between bad acts that reflect movement culture and bad acts that don’t, the those occasional moments of jackassery aren’t a huge deal.

Which is to say that no, Jon Stewart, some idiot taking a dump on a cop car (ten days ago!) isn’t going to “derail the movement.”

No. What derails movements isn’t random acts of jackassery. What derails movements is the disproportionate attention such acts sometimes draw, and the endless hand-wringing that sometimes ensues.

Luckily, that hasn’t happened here. A Google search on the cop car story returns nearly half a million hits, but that’s less than a tenth of a percent of the half a billion hits that “occupy wall street” gets on its own. The incident got a bit of attention when it happened, then mostly sank under the waves as actual news kept happening and folks moved on.

But not everyone is able to resist a poop joke, and not everyone is able to resist an opportunity to lecture activists about “optics.”

And so last night Jon Stewart and his Daily Show writers pulled down their pants and squatted.

Naughty, naughty.