Recently, some users that have their avatar generated by (or just imported from?) Google have a broken avatar, since Google no longer provides an image at the given URL, but a 404.
See https://cs.meta.stackexchange.com/questions/1581/my-picture-is-missing-on-my-profile-page, for an example.
Now, this isn't really the fault of SE, but there may be a large amount of users that are impacted by this (for whatever reason Google did this).
So, how can or should we help these users? I can think of two types of solutions:
We can inform the impacted users somehow and provide guidance on how to fix their avatar. This should be easy, but this may leave a large amount of figures that will remain broken.
If the URL has changed to something predictable, an SE developer might be able to run some update and fix everything automatically. That is nice, but may be next to impossible.
What should we do?