The network wide Alert system is being retired. No Bitcoins are at risk and this warning may be safely ignored. Upgrade to the newest version of your wallet software to no longer see the alert.

Reasons for Retirement

The network wide Alert system was created by Satoshi Nakamoto as a means of informing Bitcoin users of any important information regarding Bitcoin. It has been used in the past to inform users about important network events such as accidental blockchain forks. However, the Alert system also represents a large source of centralization in Bitcoin. The holders of the singular Alert Key can at any time send an alert which could affect the entire network. As more developers join, the Alert Key is given to others, but cannot be taken away from those who have left. This has led to the Alert Key potentially falling into the hands of malicious actors who could use it to disrupt the network. Because there is only one Alert key, it is not possible to prevent former developers from sending an alert nor is it possible to identify who sent an Alert.

In addition, the Alert system is primarily Bitcoin Core specific. Many other wallets have their own systems in place but still must have handling for the Alert system because it is network wide. Something specific for one software should not be imposed on the entire network.

The Alert system has also lost its usefulness. It is no longer necessary to use it to inform users about problematic network events as users can easily get their information from any major Bitcoin news outlet.