But taking pictures (and then spreading them to your followers) is a very, very clear no go.
Yes, these kinds of jokes are immature and this conduct was ill advised.
That said, taking ambush pictures of nonconsenting parties and very publicly shaming them shouldn't be your go-to response. I'd say that response was completely disproportionate to the initial crime.
Far better to throw an (in person) "come on guys, be professional" their way and escalate from there. If that's too confrontational for your tastes, go talk to one of the PyCon volunteers and ask them to step in. I think it's kind of ridiculous that they (PyCon staff) didn't get a chance to resolve this issue discretely and had to hear about it alongside however many thousand other people.
http://pycon.blogspot.co.uk/2013/03/pycon-response-to-inappr...
It's not clear whether that happened before or after the photo was posted.
Edit: the code of conduct also says "Public shaming can be counter-productive to building a strong community. PyCon does not condone nor participate in such actions out of respect."
Where is that? The only code of conduct I have found is here:
https://us.pycon.org/2013/about/code-of-conduct/
The only mention I see of photography is in this sentence.
> Harassment includes offensive verbal comments related to gender, sexual orientation, disability, physical appearance, body size, race, religion, sexual images in public spaces, deliberate intimidation, stalking, following, harassing photography or recording, sustained disruption of talks or other events, inappropriate physical contact, and unwelcome sexual attention.
I think you could make a reasonable that this is "harrassing photography." (I disagree, but I think it's a matter of opinion.) I don't see anything about photography requiring consent, although the code of conduct is shorter than I expected (the "Longer Version" on that page is not much longer than the "Short Version"). Is this just a summary of a longer document somewhere?