There is no way that you can sue the people responsible for DDoSing your system. Even if you can find them ... and you won't ... they're likely as not either not in your jurisdiction (they might be in Russia, or China, or Bolivia, or anywhere) and they will have a lot more money than you.

People here on HN are laughing at the UKs Online Safety Act for trying to impose restrictions on people in other countries, and yet now you're implying that similar restrictions can be placed on people in other countries and over whom you have neither power nor control.

Facebook and Bing sometimes are 80% of my daily hits and don't respect my IP bans and other bot filterings at all. You think I can just sue them and have any change to win before being broke?