In response to Monday's events, I just added the page: https://en.bitcoin.it/wiki/Alerts_mailing_list:
The Bitcoin Protocol specification supports the broadcast of Alerts. An unofficial email relay is now provided that rebroadcasts these block chain related alerts. To subscribe via email send an email to [email protected] and you should receive an email asking you to verify your subscription.
Alternatively, you can browse to the Google Group for the list:
https://groups.google.com/forum/#!forum/bitcoin-unofficial-alerts
By default Google Groups does not send emails, so when you sign up you will likely want to choose to get notifications via email.
Verify alerts and obtain the latest status information
If you receive an alert you should immediately verify it is official by running "bitcoind getinfo" (but see notes below), go to bitcoin.org to obtain more details and background, or join the #bitcoin IRC channels on freenode to obtain the latest information.
Notes
- Alerts are broadcast to a specified range of bitcoin versions.
- The email relay uses a specially patched version of bitcoind that should report and therefore relay any alert broadcast for any version.
- You will therefore have to verify whether or not the alert is relevant to your particular version of bitcoin client.
- Alerts are also independent of blocks or transactions, and have a defined time-to-live.
- The email relay polls bitcoind every six minutes