block amazon, ovh and digital ocean

for 3 of small web servers i manage i have blocked all ips from amazon aws, ovh, digital ocean and contabo. that's about 92 millions ip's.

the block is running easy and fast, without any performance issues, with ipsets of type hash:net on a 15 year old processor.

first day after this block: 

 -spam, scans and all sorts of malicious activities against web sites or web services droped about 85 %.

my servers are located in romania, eu. //

these are small servers but still, every minute there are more than 30  tcp/udp blocked packets.

by the way, worst scammers and hosting companies in eu are from dutch, german and france teritories.  i still think how to block these contries from accessing my servers.