Have you ever seen a retraction or correction of a news story?
They are rare and often inconspicuous when they do appear. After all, nobody likes to highlight their mistakes.
The real problem, however, is that retractions and corrections do little to erase false impressions that have already been published. Words -- especially in the social media world of instant publication -- are very hard to take back.
For this reason alone, law firms must have social media policies.