The tactic seems questionable. I'd rather give money to people who provide legal assistance to folks getting hassled by debt collectors, and spread information

The tactic seems questionable. I'd rather give money to people who provide legal assistance to folks getting hassled by debt collectors, and spread information about people's rights under the FDCPA and other laws. The reason for that being, buying up bad paper raises the value of it, whereas letting people know their rights lowers the value of it. If bad paper was worth less, debt originators would have stronger incentives to work something out with their insolvent customers rather than sell to shady debt collectors.