Here is the response that we provided in the same article from which that information comes from:

"The data we collect in GhostRank doesn't contain any information about the actual ads that were seen by panel members. Rather, we simply report on the technologies that are used to deliver those ads, the performance characteristics of the URLs those technologies were seen on, and if the user blocked that particular technology company. GhostRank can't see the actual ads or anything about the criteria that were used to target them."

But, if you are at all uncomfortable with sharing any data after what you read, feel free to go into your Ghostery settings, click Support Ghostery, and make sure both boxes are left unchecked. That will ensure you never send any data of any kind our way and you can continue to use the extension without ever sharing anything.