Yep, I used Piazza extensively in school. As a tool, it was actually pretty good and students used it heavily. Unfortunately when they shifted their focus to selling students to top companies it soured the taste in my mouth a bit.

I see a lot of positives in that system, but it feels like a way for companies to more easily ignore candidates who aren't from top schools. My concern would be further ostracizing qualified students who don't go to top schools.