A number of iPhone owners have reportedly observed large, unprompted data transfers that occur overnight.
According to an Apple forum member known as Cnpeyton, "something" mysterious happens at 1 or 2 am every morning.
"With the changes to the data plans, I decided to look at my wife's data usage on her iPhone. What I found is odd and a bit concerning. Overall her data usage is pretty much nothing, except for something that occurs every AM," wrote Cnpeyton.
"The amount of data being transferred is REALLY high if you ask me, as high as 75336KB back on the 17th. I called AT&T support and they said it was the phone updating or mail being downloaded, basically they have no idea. [But] I have the mail set to fetch manually already."
Meanwhile, Gizmodo's Jesus Diaz noted that the enigmatic transfers typically amounted to "dozens of megabytes" per episode.
"There are many theories about the reasons behind these downloads. From the people with the tinfoil hats - who point out that it may be part of an alleged NSA domestic surveillance program - to others who point out that Apple or AT&T may be collecting some kind of usage information at night," explained Diaz.
"[But] it wouldn’t be the first time that Apple has collected data unknowingly to users. Recently, they disclosed they collect, store, and share real-time user location data. However, these transfers are way too big to be little bits of information. So the questions are: Who is downloading this information? What information is being downloaded? And, if it's Apple or AT&T, would it count towards your data plan?"