Securing yourself means not being vulnerable to the attacks. Who cares if you are exposed to an internet radiation banana equivalent? Why worry? You'll hurt yourself more from the worry than from the radiation.

Blocking huge IP ranges is knocking yourself half offline, and it doesn't even stop you being "attacked". I'd start blocking if and only if there is some actual problem for your server (e.g. excessive CPU or bandwidth usage), not just because big bad scary cloud.

> Who cares if you are exposed to an internet radiation banana equivalent?

Me, because i would like to read all of the syslog without meaningless noise.

Then don't log the noise. Every log gets filled with noise if you aren't careful about choosing what to log.

Nonsense. There is no log level that separates between noise and legitimate data.

Then stop trying to separate it and just acknowledge these logs are (almost?) worthless?