Since they use the muting function, you can check the list at this page:
https://steem.makerwannabe.com/@minnowsupport/followed/1
Everyone muted by @minnowsupport is on the blacklist.
You could also use an API to pull information from the blockchain. Information around that is in the developer notes in Steem's github.
One can also go to this link which is a tool by @inertia that allows a simple table view of follows/mutes.
That's a much more usable format. Thank you!
I use it to verify that my spreadsheet is accurate on a regular basis.