Worse yet, most police are at least classist. Poor neighborhoods are policed far more heavily than wealthier neighborhoods.
What happens when there's already heavy policing of poorer neighborhoods, and police are trained to "get the bad ones off the streets"? They look for any excuse to arrest and prosecute people in those neighborhoods. Once you have a felony conviction on your record, you're basically unemployable for 10 years (in the US at least). Thus continuing the cycle of poverty. And of course, minorities tend to be disproportionately poor.
This makes that cycle worse. Anyone in the proximity of such a felon due to this data collection and aggregation now becomes a target by the police, raising their chances of getting caught up in the legal system and experiencing life-long consequences because of it.