I honestly wonder if Sqreen just suddenly learned about Tor. Tor doesn’t really enable attackers, it just limits them. It’s a matter of convenience. If you block all Tor users, an attacker will just pay $10-15 an hour on the darknet for boxes that can perform the same Slowloris attack and potentially a higher-bandwidth attack.
This is akin to bringing a knife with you into the bad part of town for fear of robbery. Yes, you’ll discourage the 0.001% who would be discouraged. The rest of the people will shoot you.
This is just content marketing for them. They are selling a SaaS security product that’s geared towards blocking “suspicious” web requests, after all. To their credit, they are not proposing blocking Tor users as a first choice solution.
“As we have seen, banning Tor users from your application could be a crucial point in securing your business”
Could it really be a crucial point for securing your business to block certain IP? It really sounds like if that’s the case you more likely have a major issue and should rethink your security.