True - and their lack of rate limiting ended up letting someone overwhelm their servers, knocking them offline.
They put out a blog asking people not to scrape afterwards. A simple google will be much fast than asking for sources.
Archive.org is a non-profit without the capacity to serve that many requests. An excellent resource for people to use carefully, but not a treasure trove for bots to scrape down to the last bit.
Would be cool if they introduce some reasonably priced access for mass scrapers. Should make some nice income in addition to donations, and a valuable service to community.