Even if you trust them to "don't be evil", i.e., don't "collect" it, they could accidentally retain it, get compromised, waste users' bandwidth, etc. All of which encroaches on privacy and personal freedom, even if it can be said they're not "collecting."

See also: NSA's definition of "collect." [0]

P.S. This is assuming the portrayal is accurate. People in the thread are saying it's not. Default-enabled stuff like this is kind of scummy IMO, though, either way.

[0] http://www.slate.com/articles/news_and_politics/politics/201...