Michele Berry, a fellow Ohio attorney, has posted an article on Lexis about the DC Circuit GPS tracking case, Maynard. The article (for Lexis subscribers) is here.
In the article, Ms. Berry suggests that "the Maynard decision provides plenty of guidance and authority for how to craft creative arguments in analogous Fourth Amendment situations." She points to the use of cell tower information and the contents of e-mails.
An important caveat, I think, from this decision. The argument from Maynard is focused on the fact that the aggregation of data raises unique privacy concerns. I think it this is significant, as law enforcement attempts to focus in on where a person is at a particular moment in time, or the address information from a single e-mail, are more likely to be upheld by the court.
You can find the article I am publishing on this issue here.