[Sto Zvirat]

If a religious group didn't like a newspaper and they went out and took all the prints and covered up certain words and removed certain stories and put the papers back on the rack...that wouldn't be censorship?

Definition of CENSORSHIP 1 a : the institution, system, or practice of censoring b : the actions or practices of censors; especially : censorial control exercised repressively

http://www.merriam-webster.com/dictionary/censorship

Where in there does it say its a government act?

[Egg]

You’re not very good at looking up the meaning of a word, are you?

[Egg]

If a religious group didn't like a newspaper and they went out and took all the prints and covered up certain words and removed certain stories and put the papers back on the rack...

Strawman. Once again, this is a private transaction between two willing parties. No one is forcing their views upon anyone.