I would imagine the cricket update came through the telemetry system as opposed to a broadcast message. There would masses of info going through the data link while the aircraft was in-flight, you may even find updates were included in the transmissions to all aircraft in the fleet. The newspaper seemed to think differently but I am used to having an opposing opinion, or view, to the reporter anyway.
I am aware how the ACARS and FMC data link systems works, its just seems this was reporting of Radio/Data communication that has been reported by the non recipient, which is illegal.
Is it illegal to re-transmit the info if it was willingly released for public info by the intended recipient???
The pilot requested info (cricket update)from their OPS centre via datalink, the pilot recieved the info (intended recipient) and then willingly passed that info to a member of the public for their consumption. The member of public then, without any restrictions on how/what they do with that info, made it public again via a social media medium.
If the story had been published without a photo of the datalink message, would this whole debate be moot!?
I think it would only meet the criteria of illegal transmission if neither of the parties involved in the transmission knew it would shared. As the recipient of the info knowingly and willingly shared the info, then I suggest there has been no wrong doing.