I couldn't even guess the episode, but Marco has stated on is 5by5 podcast that he doesn't collect user information and only dips into user information grudgingly. I'd be surprised if this came from him as according to his statements he finds holding any user information that could be described as private unpleasant.
This is all based on recollection however.
Still cant find the podcast, but here is what Marco says the FBI tool, quoted from the Instapaper blog about a year ago:
>>The server was used as a MySQL replication slave, handling read-only queries to speed up the site. Instapaper suffered no downtime as a result of its theft and no data has been lost.<<
>>Possibly most importantly, though, the FBI is now presumably in possession of a complete copy of the Instapaper database as it stood on Tuesday morning, including the complete list of users and any non-deleted bookmarks. (“Archived” bookmarks are not deleted. “Deleted” bookmarks are hard-deleted out of the database immediately.)
Instapaper stores only salted SHA-1 hashes of passwords, so those are relatively safe. But email addresses are stored in the clear, as is the saved content of each bookmark saved by the bookmarklet.
The server also contained a complete copy of the Instapaper website codebase, but not the codebase of the iOS app.
Linked Facebook, Twitter, or Tumblr accounts only store their respective OAuth keys. Linked Evernote accounts only store the Evernote email-in address. Linked Pinboard accounts, however, store plaintext usernames and encrypted passwords, and the encryption keys are present in the website source code on the server. <<