Facebook billionaire Sean Parker says data overload is a bigger problem for the site’s users than the much talked-about privacy issues. He also acknowledges Facebook is losing “power users” to Google+, but doubts this poses a serious long-term threat.

Parker, who co-founded Napster and is best known in the mainstream for being portrayed by Justin Timberlake in The Social Network, was speaking at the Web 2.0 Summit event in San Francisco, said “I don’t think privacy is an issue. That may be controversial, but I don’t think that’s Facebook’s biggest problem.”

Instead he believes the problem involved those users who contribute the most content and network the most widely. Parkers believes such users now feel a lack of control simply because they have so much data to deal with when trying to control what information they see and how they share it. He pointed to Facebook’s recent enhancements to make it easier to share with specified users only, seen by many as a take-off of the Circles feature on Google+, as a way of addressing this.

Discussing the prospect of Google+ taking Facebook’s crown, Parker acknowledged it was a possibility, simply because Facebook had done the same thing to MySpace when that seemed unlikely. But he noted that for this to happen “Facebook would have to screw up royally and Google would have to do something really smart.”

According to Parker, that’s simply because the power of the network effect means that for many individual users, making a switch isn’t worthwhile unless both their friends and even friends-of-friends also make the jump.

(That’s a very valid point, and I’d say far more powerful than the situation with MySpace and Facebook. While MySpace had a huge user base, it was largely people of a similar demographic. Facebook appeals to a wider range of people, making a stronger set of network chains.)

Parker also discussed the integration of Facebook and Spotify, saying the latter was an attempt to finish the “dream of frictionless-free, tiered service that enables music sharing” which Napster began. He believes the partnership could make it possible for bands to breakout purely through word of mouth even without the support of traditional media.