Considering the level of intrusiveness of Beacon, there is a high level of complacency regarding Beacon, and an unjustified level of faith that it will just go away because of its lack of popularity. The Facebook group protesting Beacon has only 55 users.
I've got news for you. If you know what Beacon is, you are in the minority of Facebook users. Most Facebook users don't know, will never know, and will never care. That is why it is ludicrous to suggest that there should be an "opt out" feature. It is even more ludicrous to suggest that Facebook will back down from the Beacon.
Despite initial reluctance, and taking some minor steps back from its original plans (and you can bet it will step back up in the future), Beacon will go ahead as planned. Over time, the few people who even noticed its existence will get used to it, or opt out of Facebook. And over time, the big brands will recognize that nobody cares anymore and they will all opt into Beacon.
It dismays me to see how the big social networking guys are dealing with this. They are blogging about it. They are setting up groups against it. They are telling anyone who will listen how to block it.
They aren't quitting Facebook. Gentlemen, and I respect and love you all, but you are behaving like crack addicts. You complain about the damage to your health but you ain't quitting.
Believe me, if Jeff Pulver sends a message to all 4000 of his friends that he is moving over to MySpace (or wherever), 90% of us will up and follow him. If he and Robert Scoble did it, all of us would move. Until they do, though, none of the rest of us can afford to.
Facebook is making some clear strategy statements in its developments. One, it is a closed system. You can't export your friends or applications. Two, your privacy will be eroded over time. No protest is going to change that, because those are the basic inherent features and architecture of the Facebook philosophy of How It's Going to Work.
Beacon will not go away. It will only get stronger and more invasive over time. The people who are complaining are fewer than 1% of users. They may think they are the "influential" users, but so far, well, let's just say I am not impressed by the influence on Facebook.
IMNVHO, the only solution is to leave Facebook, and only the thought leaders can do it. If they don't, I predict that within 3 months we will forget that Beacon ever existed, but the advertisers won't.