[usr1106]

Certainly this has its benefits. But how often does it happen that someone types (especially pastes) something into the wrong channel erroneously? Not that uncommon in my experience. That's much more dangerous if you have business partners/customers in the same chat system. Sending a message to the wrong email recipient is much less common in my experience.

[tptacek]

The people that use this feature would generally have two Slacks open anyways, which already presents the same risk.

[aeternum]

This should be easy to solve in the UI. If you haven't sent a message to a shared channel in the last x hours, require a confirmation.