With a lot of people working for corporations, many think they have signed a contract; this is unlikely and in most cases they have not.

A contract requires the signatures of at least two people, meaning what is written within that contract only applies to those who signed it.

What most people have actually signed is nothing more than a service agreement, meaning it only has one signature.

With only one signature, then it is only charged by one person, who has control over the document.

No one else can change this service agreement, as their signature is not marked on it.

If anyone should attempt to change this service agreement, without their signature on the document, they would be violating the rights of the signee.

As no one would ever take liability over any changes to this service agreement, all the power is with the signee.