No, Leo doesn't feel this is something to be concerned about. Google recently updated their Terms of Service when they introduced Google Drive. This quickly became controversial because the way the Terms of Service were written was disconcerting. This is the part that concerned Louis (and many others) the most:
When you upload or otherwise submit content to our Services, you give Google (and those we work with) a worldwide license to use, host, store, reproduce, modify, create derivative works (such as those resulting from translations, adaptations or other changes we make so that your content works better with our Services), communicate, publish, publicly perform, publicly display and distribute such content.
Leo pointed out the paragraph before this one, though:
Some of our Services allow you to submit content. You retain ownership of any intellectual property rights that you hold in that content. In short, what belongs to you stays yours.
The reason Google included all of this language is because of all the technical things they need to do to merely provide the service. They have to be able to move files, make copies of them, cache them, etc. Google's lawyers are just playing it safe and asserting all rights so they can't get in trouble for anything. Leo called attention to the sentence right after the one Louis recited too:
The rights you grant in this license are for the limited purpose of operating, promoting, and improving our Services, and to develop new ones.
They are not saying they can take your stuff and do whatever they want with it, even though it states that in the Terms of Service. Leo does believe it was a mistake on Google's part to not have realized this would be poorly received by users, but it is necessary for them to be specific about what they need to do. This same scenario has happened with many other tech companies, like Facebook and Pinterest for example. There's no cause to panic, though -- they aren't stealing your data.
Leo highly recommends reading this article by Nilay Patel of The Verge: Is Google Drive worse for privacy than iCloud, Skydrive, and Dropbox?