As troublesome as Twitter, Facebook, and Google Plus can be, some of their epiphytes are just terrible. Personally, I harbor a surly attitude towards Klout because there's no opt-out option - there is no way (that I could find) to say to them, "count me out." I realize that they have a lot of number-crunching to do, but not having an opt-out mechanism makes them look skeezy. If they fear that too many people would use an opt-out mechanism if it were available, that in itself is a problem! They should provide the mechanism and be honest to themselves about whether their business model is viable - because if they get a lot of opt-out responses, they should probably quit or pivot.