I made an effective low fidelity API to the graffiti data.
You can now query with a location and get back results in chunks of 25. You can page through the results via the page attribute.
I’m conscious that there is currently no key/secret pass system. I have what I need for the application feed, so I’ll go from here.
http://www.graffpass.com/find.json?page=4&search=40.714352999999996%2C-74.005973