You can’t look around to see if someone might be trying to eavesdrop, because Slack always is. The security and privacy properties of Slack are vastly different than face-to-face conversations that it’s replacing. That data is not end-to-end encrypted, which means Slack can read it, law enforcement can request it, and hackers - including the nation-state actors highlighted in Slack’s S-1 - can break in and steal it.' 'Right now, Slack stores everything you do on its platform by default - your username and password, every message you’ve sent, every lunch you’ve planned and every confidential decision you’ve made. In a 2019 op-ed in the New York Times, the Electronic Frontier Foundation’s Gennie Gebhart summed up the problems with using Slack: So this is a good time to remind everyone, while Slack can make communication and team coordination easier: your Slack messages are not as private as you may think.

Yes, even here at Freedom of the Press Foundation, we use Slack for coordination across multiple teams.

When Slack went public in 2019 with a valuation at $23 billion, Nieman Lab suggested that there might be more newsrooms that run Slack than use Microsoft Word-it’s everywhere. In late March 2020, Slack announced it had significant user growth, nearly doubling the number of new customers. Slack, which was already a key tool in many newsrooms, has reached new levels of usage. As the COVID-19 pandemic hit, workplaces were forced to rapidly switch from in-person settings to fully remote.

Slack retention policy