That said, many of these firms also ingest data from aggregated sources, so their research would activity be very difficult to accurately track via IP presence.
The reason for not having your own computers is because you can't afford them. A consideration for upstart funds, not a problem for RenTec.
Because you don't want anyone to have access to your code and data.
If you found out that Facebook is running on AWS, wouldn't you find that strange?
Therefore, A) companies that operate at a scale where the only upside disappears, and B) companies where the cloud saving outweights their expected liability cost, both will have their own datacenters. Facebook is clearly in category A, RenTech is clearly in category B. This is my understanding anyway.
Filings are subject to change due to errors, updates, etc. It's cheaper, easier, and less error prone to just scrape and overwrite data than search for any updates.
I may have been heavyhanded in saying that the firms are rescraping the entire universe of filings on a daily basis, but I guess my point here is that these numbers can very easily be skewed and are generally a pretty poor indicator of actual data access.
Filings are subject to change but they are restated, not modified in place. That said, anything goes on the site.
The only real reason not to scrape everything on a continuous loop is that there is a rate limiter in place, so you may end up impeding your intake of new data by loading yourself down with old jobs to handle.