Do I need to warn my class about a potential privacy loophole in Piazza?

Date: September 2019


Dear Deans,

This query is related to a weakness I found with Piazza. As a TA last semester I noticed that Piazza provides very detailed posting statistics of each student in real time. In tabulating this information it also counts anonymously posted queries and replies. Thus, if I am pathologically vigilant and monitor the stats column continuously, then I can trace back every anonymous post to its contributor as soon as it appears by tracking whose statistics have just increased by one. Although doing this for every student is impractical, it’s much easier to keep tabs on the few students who post frequently and appear at the top. In at least one case, I myself was a top poster and anonymously wrote something which the instructor would not care to see – now I feel that the prof actually knows it was me. I have written to Piazza about it and received the usual polite but insignificant response. 

So the question is, as a TA do I need to warn my class about this potential privacy loophole in Piazza? 


Privacy-conscious TA


Dear Privacy-conscious TA,

Thanks very much for your thoughtful question. To address your question, I consulted with staff at Cornell’s Center for Teaching Innovation (CTI). A learning technologist at CTI supports Piazza. CTI staff agree with your assessment that students should be made aware that “anonymous” in the Piazza case is a “thin veil.” Students should be alerted to not post anything they would not feel comfortable associating their name with. You could explain how you came to this conclusion, describing the clever system test you did. While it may be unlikely for an individual student to be identified, it is a possibility as you have demonstrated. Students should be made aware of this. CTI staff acknowledged that the issue should be addressed on their website as well.

You could also reinforce with your students what the purpose of Piazza is – to ask and answer questions related to course content in an efficient manner. That may help emphasize appropriate and respectful protocols that should be followed with Piazza, i.e., use the system for learning/questioning about course content, not for personal comments or criticisms.

I hope this helps address your question. Thanks again for your vigilant thoughtfulness in using teaching/learning tools.

Warm regards,


Barbara A. Knuth
Dean of the Graduate School