> If the amount of data is large enough and with enough parameters, removing PII doesn't do anything to protect privacy.

Honestly it doesn't have to be that large. We see this all the time with data websites or apps collect. Sure, you remove John Smith's name, but you still have his GPS coordinates. For the school, you remove Professor Smith's name, but you have a professor who teaches CS 123 and has 4 graduate students. You bet you can guess who that is.

I really do support open data, especially about public institutions, but at the same time we are in an era where this information is quite powerful. Seems to make a case for something like homeomorphic encryption or something, but will that even stop these collisions?