I'd also like to know whether this information can be or has ever been used in court as evidence. "Where were you on the night of such and such...?" may become a question of the past. Frightening.
Oh yeah, it does get used in court in the US. I paid attention to a murder trial of a neighbor that happened nearly a decade ago, and they presented evidence of his cell tower connections contradicting his story of whether he was in a certain state at the time. It was by no means a substantial part of their case though, they were just piling things on. But yes, it's definitely admissible, I assume it happens all the time.
Falls under the category of circumstantial evidence, which can certainly tip the balance beyond the "reasonable doubt" criteria if there is enough of it.
