The Aggressive Blocking feature is a tool we use during severe cases of click fraud as a sort of a "Doomsday Weapon", our last resort option.
Enabling Aggressive Blocking allows ClickCease to auto-block ranges of IP addresses in a hyper-aggressive manner. The direct result will be that the amounts of IP's blocked will rise dramatically, but that could also include potential "genuine" customers as well as attackers.
Use it after careful consideration and after you've allowed the system to collect sufficient data regarding your click fraud situation.
To enable Aggressive Blocking, go to Domain Settings > Manage Auto IP Blocking, and scroll down to toggle on Aggressive Blocking: