Apple Tells Leaker to Snitch on Sources or It Will Report Them to the Police (vice.com)

Well, it's Vice.

If the iPhone prototypes were taken from the premises of the factories, it‘s theft and the Twitter user is selling stolen goods, I assume?

They say stolen several times but seem to lean towards calling it “leaking”. That said, the letter from Apple seems to reference trade secrets rather than theft of property.

It should be both.