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A former Gizmodo writer changed his name to ‘Slackbot’ and stayed undetected for months
(www.theverge.com)
This is a most excellent place for technology news and articles.
Slack Business/Enterprise supports SAML single sign-on. At any scale larger than a single team or two this is probably the better way of handling it, then the account gets disabled as soon as it's disabled in the identity provider. Otherwise if I remember right Slack accounts are tied to the email address and users can set their own display names. I used to administrate Slack for ~60 users but now we're on Teams.