Do you follow our tweets and Facebook posts? If not, you missed the discussion about your rights when you are denied boarding a plane when you have a valid boarding pass.
Most airlines overbook many of their flights. This means they sell more tickets than there are seats available on the plane. They do this because they have historical data that some people with tickets will not show up for their flight. If too many travelers show up for the overbooked flight, then there are Federal Regulations which govern “oversales” situations. This includes compensation for being involuntarily denied boarding and what has to be in the written notice provided by the airline.