To a certain extent, this is always a concern. The loss of our privacy, and the control or monopolization of our information by single private sources (these being linked issues) are always an issue in this world. Think of email, for example. It may be an open protocol accessible with open applications, but it is hosted on individual, private servers. Where do the vast majority of people go to for their email nowadays? Gmail. They go to Google, rather than to their own isp's servers or any other ones. Google has, to a large extent, managed to monopolize much of our information...
Email is weird that way, though. There was a time when EVERYBODY had an AOL email. Then it was Yahoo. Then it was MSN/Hotmail. Now it's Gmail. I'm not really afraid of Google, any more than I'm afraid of any other big company. They're all crooks in some for or fashion.