I understand that a contract can be created by the actions undertook by the involved parties. When you visit a website you agree to the ToS by using the website (regardless if you read it or not). Related to my previous question I had an employer deduct a small fee to process my payment, they argued that they were allowed to because it stated they would on the website I had to use for the job. Does this even form a contract?
Another example, I went to a library and started using a computer. The librarian came up to me and pointed out a sign saying I had to pay before using the computer (which is uncommon where I live). Is there a contract formed by just having a sign? Hypothetically could the library sue me for not paying?
Further, if there was a sign on the door to a private building saying you have to pay $20 to enter, if you didn't read the sign and entered, could the owner demand $20 from you?