Snopes is not always right. I don't know about the Starbucks thing, there's been articles about it on FR - a search would work.
A couple of years ago I checked out Snopes concerning some Hitlery Clinton stuff I knew to be true (after having read a number of books about the Clintons) and Snopes got it wrong. Actually I checked a couple of things (unfortunately I can't cite chapter and verse.)
They were started by a liberal husband and wife team, and they get their info on Google just as anyone else does.
They are not infallible and they are biased.
Snopes is not always 100% correct, but the sources they cite are generally verifiable. If you read the Starbucks case, you can see how these types of rumors get started.
Just look at how many posts in this thread state incorrect information about Target ownership. It would be so easy to check the history of Target stores, but too many are lazy to do that. And people wonder why so many fall for the lies of the left, or the MSM? Fact is most people take alot of what they hear has fact until proven otherwise, rather than having some healthy skepticism about stories that seem far fetched, or a bit too convenient.