In my opinion, background updates are awesome. I love that Chrome is always up to date without my ever even having to think about it. Let's look at why.
I have a little philosophical question: what’s the difference between Google Chrome silently updating in the background without me ever giving it explicit permission to do so and malware updating itself in much the same way and getting new commands to wreak havoc? In fact, I believe Google Earth also updates itself with no explicit permission. At some point, it suddenly showed up in my frequently used programs as a new program even though I already had it. If there’s a clause in the User Agreement that says they can, it becomes a legal issue where the question is whether they can just change the Agreement after a user agrees to a different version of it.
Well, I’m not a lawyer, so I’m not going to address legal issues. But I bet that the agreement probably contained terminology so you gave them permission to do silent updates.
It’s one of those things about legalese. Lawyers can always interpret it in a way that allows them to say that you agreed.
The concern that I have with your question is that you seem to be very distrustful of these silent updates and consider them akin to malware.
I strongly disagree.