His lawyers argue that feds needed a "probable cause"/a warrant to seize that information, but they failed to convince the Court of Appeals in May that the lack of one violated his right under the Fourth Amendment. Reuters noted that under the federal Stored Communications Act, feds don't need probable cause to request for a customer's records. They only need to show that there are "reasonable grounds" for the request and it's relevant to the investigation. Wondering whether feds actually need a warrant to acquire your cell site data or not? According to Ars Technica, different courts rule as they please. It's definitely confusing, and the Supreme Court declining to hear Davis' case makes the situation even more so.

[Image credit: Getty/AndreyPopov]