Slack had to make a rather unpleasant announcement on Friday:
We were recently able to confirm that there was unauthorized access to a Slack database storing user profile information. We have since blocked this unauthorized access and made additional changes to our technical infrastructure to prevent future incidents.
The good security news to come of it: two factor authentication is now an option. I immediately enabled it for my Slack logins, and you should too. In fact, I’d recommend enabling two factor authentication anywhere you can. A good list of services that provide it can be found here: