This doesn't seem limited to NY as if you run a google image search for missing unicorn, you'll find lots of the exact same flyers but with different numbers. It's probably something lame but you never know.
"New Yorkers have been looking for this beast, a female unicorn with a friendly disposition, since thousands of posters for it sprung up around the city.
There's a phone number to call if you think you've seen it -- (917) 675-4783 -- and audio from some calls, as well as supposed images of unicorn sightings, have been placed on the unicorn's Web site, missingunicorn.com...:
http://weirdnews.about.com/b/2010/11/29/have-you-seen-this-missing-unicorn.htm
