Through the years so much has been tried, Cert Pulls, etc., but The DTCC does a terrible job, the MMs don't care and the SEC can't enforce jack down in pink land except to just freeze and hurt the actual small fry. The DTCC let 100 of millions of fake BCIT shares get circulated when BCIT only had 14 million A/S. So when the CEO complained the DTCC put a global lock on the stock and it hasn't traded to this day and the CEO even proved his case in court and the issuers of the fake shares are in jail and have been fined. But, DTCC never made anyone cover.