Everybody talks about Big Data nowadays, but I never see mentioned one straightforward use: real estate investing.

The police have slowly been ramping up their information technology over the last 25 years to look for "crime hot spots," as recommended by Bill Bratton.

Can you use this data for real estate investing purposes? Scan the data for "crime cold spots"—low crime blocks in low cost neighborhoods—because they might be promising for gentrifying. 

Traditionally, cops have been interested in second careers in real estate—see, for example, Harrison Ford in 2003's Hollywood Homicide—because they drive around all the time and can notice neighborhood trends first. But this kind of data would make real estate trend-spotting even easier.