Not that easily. A sophisticated attacker is going to be using a lot of different throwaway IP addresses. One of the common ways to (try to) prevent this are of

Not that easily. A sophisticated attacker is going to be using a lot of different throwaway IP addresses. One of the common ways to (try to) prevent this are often how you end up with stuff like "all IPs we think are AWS or data centers or [...] are blocked from our service."