For the 97th time the airline is not allowed to remove someone from their seat because the airline wants the seat. Once a person is seated the airline needs a cause to remove. It is very clearly stated in their own rules on their website. The CEO admitted they were wrong and said it should never have happened and it will never happen again.
We don’t get to treat someone like a nonperson because they have committed and were punished for a crime in the past. They have the same rights as any other citizen except as mandated by law such as not being able to vote in some situations or have a liquor or gun license.
https://www.united.com/web/en-US/content/contract-of-carriage.aspx#sec9
I do see this though:
Safety – Whenever refusal or removal of a Passenger may be necessary for the safety of such Passenger or other Passengers or members of the crew including, but not limited to:
Passengers whose conduct is disorderly, offensive, abusive, or violent;
Passengers who fail to comply with or interfere with the duties of the members of the flight crew, federal regulations, or security directives;
Passengers who assault any employee of UA, including the gate agents and flight crew, or any UA Passenger;
Passengers who, through and as a result of their conduct, cause a disturbance such that the captain or member of the cockpit crew must leave the cockpit in order to attend to the disturbance;
You do know that there were three other passengers that were "involuntarly" removed from the aircraft after boarding without incident, right?