EFF: What You Should Know About Online Tools During the COVID-19 Crisis
https://www.eff.org/deeplinks/2020/03/what-you-should-know-about-online-tools-during-covid-19-crisis
"By default, Slack retains all the messages in a workspace or channel (including direct messages) for as long as the workspace exists."
"Zoom allows administrators to see detailed views on how, when, and where users are using Zoom."