I find it more worrying that people are hand-wringing obsessively over any service that collects any amount of personal data. Promoting innovation and finding creative ways to approach problems are both much more important than enumerating the nefarious ways that people or groups or governments can use the resulting data.
While it's an important cause to fight for, some privacy discussions that are consuming various parts of the tech community these days are just silly.
I don't find anything about this service incredibly worrying. I'm much more worried about what we don't know -- the data-collecting activities we don't knowingly participate in. But since we don't know what we don't know, I try not to waste away my life hand-wringing over those things either.