It's a risk but it seems likely to only be a problem in places where there are significant variations in income: if you live in a neighborhood where the average house costs $500K, your hypothetical burglar is going to assume that they're all good targets – or they'll just go to the house with a Mercedes in the driveway.
Income data can be used for a slew of criminal activity. I wonder if you can correlate the release of the data with burglaries or other crimes spiking in the relatively wealthier households, compared to their neighbors.