Privacy and covenience is always the relationship of inverse proportion. To gain more convenience, you have to give up more privacy. For example, social-networking software called Visible Path takes into account the strength of relationships, so it considers the number of e-mails the workers exchanged. It argues that it never check the content of e-mail, but to improve its function, it should consider the content of e-mails. Without caring about the content, it values a very important business e-mail as equally as an e-mail sent by mistake. The content of e-mail is important factors to decide the strength of relationships. Checking the content of e-mails is necessary for the convenience, but it means less privacy.
Another example is Amazon.com's personalization. It gives the recommendation list, and it is based on users' purchase records. It is very useful function, but it means that Amazon.com keeps the record of purchase by every customer who has their accounts. Remaining record of purchase may be uncomfortable for some users. Again, it is the problem of privacy.
There are much more examples, such as Google Earth, Google Desktop Search, etc. They are all convenient, but privacy issue always involves. As Ghahremani mentions, "people have widely different notions of what's invasive". How far users and service providers compromise on privacy is difficult issue.