Would now be a good time to remind savvy technical readers that it's crucial to have a solid grounding in ethics? It can be hard to draw a line when you work deep inside a system.
A near future version of this: data companies will profile humans who are disruptive and sell profiles to potential employers. Anybody who tries to unionize once might be unemployable for years afterwards. The homeless person on the corner might have been a former line manager at the local distribution centre who thought working conditions were unsafe. This data will follow them forever