How to delete unsent message from google hangouts? I accidentaly sent a confidental message to an incorrect contact. Fortunately, I could react in time, and I turned off my phone before it could be sent.
I opened my google hangout from the web, and I see that the message was not sent. (It was a big picture, whose upload was broken by the poweroff.)
However, now if I turn my phone on, the message will be sent.
I believe, my only way to delete the message, if

I ban the phone from my home wifi,
I remove the SIM card from it,
I turn on the phone,
I uninstall google hangouts,
Re-enable my home wifi,
Reinstall google hangouts.

However, doing these is problematic.
Does a quicker way exist for that?
If a message was not sent yet, long tapping on the message reveals a menu. This menu has an option "do not send" (or similar). Clicking it, the message will be removed.

After the message was sent, there is no way to rollback - the remote side will be able to see it.

Text messages are sent practically on the spot, thus this option has only a little relevance. However, images send on google hangouts might have an enough long upload time to break their upload.

In the case of such accident, I think it is still the best to turn the phone off on the spot, then block its all possible network access (sim + wifi), and then solve the problem offline.