BY Nick Judd | Thursday, May 5 2011

Technically Philly describes a hackathon project to find all properties owned by a given landlord by cross-referencing scraped data and city databases:

So, say, a small-time property developer wanted neighborhood approval for a zoning variance at a newly purchased property. Until Kerkstra inspired a pack of hackers, there was no easy, online way for concerned neighbors to find out other properties that property developer owned.

The resulting project, OPA Data Liberator, already caught the attention of Philadelphia's Office of Property Assessment, which is now talking about releasing more data in open, downloadable format. Partially for liability purposes, and in many cases to remain anonymous, landlords put a maze of limited-liability corporations and lawyers between themselves and their properties — which would require a little more algorithmic digging to match real estate to people.

Why is this important? Well, after the building boom of the early 2000s crashed, for example, several developers left multiple half-finished properties scattered around New York City and I would imagine Philadelphia too — and in each neighborhood, local leaders were scratching their heads about who to hold accountable. If property ownership in cities was more transparent, those conversations could have been about building community support to finish projects or zoning variances to make the properties viable for other purposes; instead, they were often about who to send the bill for graffiti removal or cleaning up hazardous conditions. Projects like this pry the lid off the often secretive world of big-city land ownership, for good or ill.

I was involved in a hack day project similar to this in New York this past January.