IP bans are equivalent to residential door locks. They’re only deterring the most trivial attacks.
In school I needed to scrape a few hundred thousand pages of a proteomics database website. For some reason you had to view each entry one at a time. There was IP throttling which banned you if you made requests too quickly. But slowing the script to 1 request per second would have taken days to scrape the site. So I paid <$5 for a list of 500 proxy servers and distributed it, completing the task in under half an hour.
It's also completely insufficient despite being better. There are so many scraper services that its just a matter of paying a small amount of money to make use of tens of thousands of IPs spread across ISPs and countries.
Using proxies to hide your identity to get around a denial of access seems to get awfully close to violating the Computer Fraud and Abuse Act(in USA, at least).
