Email gives me a reminder to keep me organized.
And the two teams I worked on that use slack killed productivity by chatting all day and sending animated gifs.
Plus, people expect email to be asynchronous. With slack, I get a mixture of immediate and asynchronous requests. So every message breaks my flow while I determine the priority level.
That sounds much more like a people problem than a technology problem, if that's how they chose to spend the majority of their time on the job.
The links in question relate to:
* Searching on GitHub for Slack API tokens
* The Slack database hack
* How the rise of ChatOps can open you up to many more issues if someone gains access to employee's Slack accounts and the risk of third-party applications which might open up things you do to more entities than you realise