Here's a picture taken outside of 13th Step, an East Village bar which was named one of Complex's "25 Douchiest NYC Bars" last year.
These people are participants in Santacon, a yearly event where your cousin's old fraternity brothers descend on New York to ruin your quiet Saturday afternoon with loud drunken jingles. Apologies for being a total GDI, but Santacon is what you get when you combine all of the terror of Halloween's rookie drinking with early onset male pattern baldness. Throw some early morning fishbowls filled with liquor in there and you've got yourself one of the most annoying days of the year.
Gothamist has a functional guide to avoiding the whole thing altogether, which is extremely useful. Basically just stay out of the East Village this afternoon and try to avoid Williamsburg tonight.
To be fair, the large crowd of people dressed in santa costumes, which probably included the ratchet sisters of AEPhi '03, kicked off this year's events with a food drive, a very nice gesture before they puke up their Penn Station breakfasts all over 3rd Avenue.