&quot;it turns out that if you know the census tracts for pickups and drop offs, plus pickup times truncated to the nearest hour, then you can uniquely identify 40% of NYC taxi trips&quot;<p>Hmmm... but if you already have those pieces of information (start tract, end tract, start hour) what would you want to get from the data?  How much someone paid?  How much they tipped?  Whether they paid with cash or card?<p>Can anyone see an obvious nefarious use for this data?