Luckily it doesn't happen THAT often. I forget the exact metric but I recall various Google Engineers saying that something like one out of a million test run failures is a random bitflip?
Cosmic rays were a theory in 70's era hardware for failures that ended up being proven to be particles emitted by the ceramic packaging itself. (Modern bitflips are have more to do with component sizes several orders of magnitude smaller.) (edit: not saying that cosmic rays aren't a problem now, just that they only became a problem as chip element sizes shrunk, and they're probably not the only source.)
Also, you can definitely stop cosmic rays, that was part of how they eliminated them as the source.
ECC RAM is for the most part relegated to server-grade components, for what it's worth. So your phone, your laptop, your router? Almost certainly not using any ECC RAM, unless you've gone out of your way to do so.
Unless you can stop cosmic rays.
Luckily it doesn't happen THAT often. I forget the exact metric but I recall various Google Engineers saying that something like one out of a million test run failures is a random bitflip?