In another telling anomaly of the meat-grinding business, many of the larger slaughterhouses will sell their product only to grinders who agree to not test their product for E. coli contamination--until after it's run through a grinder with a whole bunch of other meat from other sources...It's like demanding of a date that she have unprotected sex with four or five other guys immediately before sleeping with you--just so she can't point the finger directly at you should she later test positive for clap.