First we find out that our brokers do not need to have inventory on hand to back our electronic equity entitlements in our brokerage accounts.
Why should they? The certificates for stock held in street name are at CEDE.
Now we find out that the DTCC doesn't need to know who has sold against the certs they hold in the street's name, or keep a record of it for that matter!
Of course not. Why should they? That isn't what they do. They do not monitor, or know anything about, day to day trading. The brokerages keep records of stock loans.
At one time, DTC's Stock Borrow Program served as a clearing house for stock loans for exchange listed companies. But over the years, participants lost interest in the program, and it was shut down.