I agree to the terms and conditions

These days any thing we buy, install, download, assemble, cook and what not, any thing requires approving some lengthy, obscure, legal agreement: I agree to the terms and conditions...

For example sign up for a Nature account. A gmail account. Facebook.

Did you really read and understood every term of the agreement? Do you carefully store a copy in your safety box - just in case? If you do really read the agreement don't you get so scared that you promptly run away from this service?

Could we replace most of these documents with some common chart of the web etiquette?

1. I will use the services in a manner I judge fair, with common sense - honor's system
   
2. I respect other users and would also like not to be harassed
   
3. I'll correct my usage or be removed from the service after the owner notifies me of an inappropriate action.

What do you think?