While I am well past 24, by two decades egad, I'll throw in my two cents to help Facebook fix Beacon. I figured this is more constructive than joining the negative flash flood going on now.
Facebook Groups as Limited Opt-in
The way out is to use groups to encourage as well as letting users control Beacon opt-in. If I am fanatical about Coke, I would click yes when joining "I Love Coke" group required opting into beacon news about my recent Coke-related purchases. If I like Sci-Fi, I would join Sci-Fi groups and it would feel natural to opt-in when asked if I want my friends informed of my Sci-Fi book purchases at Amazon and not for other types of books.
Group Controlled Privacy
Members of a group should have a direct say in which beacons should be required or offered as optional for members. Minimal number of votes will hamper use of polling for this purpose but, even if not enough people voted to enable or disable a beacon, each vote can be seen as opting-in as an individual decision instead of a group decision.
Group Rewards
Corporate sponsored groups can use rewards to members to entice more users to enable beacons. Opting-in to join random drawing for limited collection of Star Wars action figures is, I think, a lot of Star Wars fans will chooses to do.
To set the world on fire, one must know which way the winds are blowing. As someone wise once said that one can learn even from a 3-year old, Facebook could learn a thing or two from pyros.