To be fair, this wasn’t a hack. It’s awesome what Crash Override and her buds did, but they didn’t hack Parler, because the webmasters at Parler are so dumb that no hacking was needed. Whenever anyone uploaded something onto Parler, the item was tagged with geolocation information. This info is tied to almost everything nowadays, but many places will remove that info. Not Parler, tho.
A bunch of nervous nellies started to delete a bunch of stuff off Parler after the events of 1/6, but none of it was actually deleted. Parler just broke the link to the info, essentially. But all the videos, images, and posts were still there, publically available, and very very easy to download through automatic scripts. The archivists also made sure that they followed Parler’s TOS to a T, which allows for automated use of info as long as it doesn’t degrade performance of the website. The archivists even made sure to build in pauses in their downloading so that they wouldn’t break Parler.
TL:DR Parler wasn’t hacked. They are just dumb.