The Ford Pinto, one of the best-selling cars of the 1970s, had a defective gas tank with an unfortunate tendency to burst into flames in rear-end collisions. Ford was fully aware of all these construction problems.
However, people didn't know that until Mother Jones magazine published a stolen copy of an infamous memo that was sent out to all senior management at the Ford Motor Company.
Ford continued to build and market the Pinto without modifications until news of the memo broke. It led to criminal charges, an avalanche of lawsuits, and a recall of all Pintos; the mess went on for years.