An airplane cabin's not a great place for indulging in "me-time" -- after all, you're crammed into a small space with a lot of strangers -- but you hope you can eat, sleep and relax en route to your destination without fear of being watched.
We're not talking about voyeuristic fellow passengers, but an even creepier thought: being scrutinized via cameras installed in your inflight entertainment system (IFE).
In February, Vitaly Kamluk -- a Twitter user who works in malware research -- was on board a Singapore Airlines flight when his wife noticed an "interesting sensor" below the inflight entertainment screen and pointed it out to him.
"She felt general discomfort of a digital eye looking at her. I believe that's a common reaction of general passengers." Kamluk tells CNN Travel.
Kamluk suspected it was a camera and Tweeted images of the discovery, tagging Singapore Airlines in the hope of getting an answer.
"I was quite surprised to actually see something like a camera and as a security expert I could imagine many scenarios of misuse of such sensors which is why I decided to ring the bell," he says.
Kamluk's post quickly gained traction on social media and Singapore Airlines responded, explaining that its newer inflight entertainment systems include an embedded camera, although emphasizing that these cameras are deactivated.
On board cameras
The fact that some aircraft seats have built-in cameras is not new knowledge.
Singapore Airlines' inflight entertainment system is manufactured by Panasonic Avionics, a US-based company that supplies IFE for many of the major airlines and French company Thales. Panasonic announced a while back that it's added cameras onto seat backs.
And in 2017, Panasonic Avionics announced a partnership with Tascent -- a biometrics and identity innovation company.
"The companies will combine Tascent's biometric identity devices, software and services with Panasonic Avionic Corporation's in-flight entertainment and communications systems to provide streamlined, easy-to-use identity recognition before departure, during flight and upon arrival," read the corresponding press release.
The idea was seat-back cameras could facilitate onboard immigration, skipping lines when you land. It was also suggested that a seat-back camera could aid payment processing for onboard shopping.
At the 2017 Dubai Airshow, Panasonic Avionics announced the latest incarnation of Emirates' IFE in First Class and Economy -- specifying it featured a camera, plus a microphone and speaker.
In the age of the smartphone, everyone holds a tiny cinema in their hand, so there's certainly an expectation that airlines will have exciting entertainment options -- a screen simply showing movies won't cut it anymore.
But has Emirates ever done anything with its on-board cameras?
"Some of our 777 aircraft have cameras that came pre-installed with the inflight entertainment hardware that we had purchased from the manufacturer (Panasonic)," a spokeperson for the Dubai-based airline told CNN Travel. "It was originally meant for seat-to-seat video calls, however Emirates has never activated it."
This echoes Singapore Airlines' comment on the issue.
"These cameras have been intended by the manufacturers for future developments," the airline says. "These cameras are permanently disabled on our aircraft and cannot be activated on board. We have no plans to enable or develop any features using the cameras."
Meanwhile, American Airlines told CNN Travel that cameras are "a standard feature," but are not activated and the carrier has no plans to use them.
A spokesperson for Aussie carrier Qantas also told CNN Travel that IFE manufacturers include inbuilt cameras as standard -- and said the airline couldn't activate the cameras, even if they wanted to.
"The feature would require software in order to be activated, which Qantas doesn't have and doesn't plan to install."
Air New Zealand and British Airways told CNN Travel there were no cameras on board any of their aircraft.
Two images obtained by CNN Travel of an IFE system on a British Airways airplane depict what looks like a lens of some kind. BA describes it as an infrared environmental sensor rather than a camera.
Improving the experience?
But are airplane seat cameras a bad idea? Some aviation experts think they could improve the onboard, inflight experience.
Joe Leader, CEO of aviation trade body Airline Passenger Experience Association (APEX) think there's several handy usages for these cameras.
As well as facilitating video chat between passengers, the cameras could look out for passengers becoming unwell or monitor cabins for suspicious behavior.
The cameras could also be used to spot human trafficking or assault -- acting as an extension of the air steward's eyes.
As for the privacy concern, APEX points out the ubiquity of cameras in 21st century society.
"Today, airline passengers are typically tracked outside the aircraft dozens of times on a typical journey through stores, security, roadways, and airports by cameras without any permission," APEX says in a statement.
"In contrast, airlines only want to use cameras in the future with permission when technology has advanced to offer personalized service improvements that passengers desire."
Hacking fears, suggests APEX, are "misplaced."
"The greatest risk to airline passenger privacy breaches come from their own smartphones, tablets, cameras, computers, and smart devices used in private settings, " says APEX.
The concern for some fliers is that even if the existence of these seat-back cameras aren't a secret -- and even if they could facilitate some cool features -- it feels disingenuous that their presence isn't advertised.
When contacted by CNN Travel, Panasonic Avionics stressed that it was committed to the privacy of passengers.
"Panasonic Avionics will never activate any feature or functionality within an IFE system without explicit direction from an airline customer," the company said in a statement to CNN.
"Prior to the use of any camera on a Panasonic Avionics' system that would affect passenger privacy, Panasonic Avionics would work closely with its airline customer to educate passengers about how the system works and to certify compliance with all appropriate privacy laws and regulations, such as [The EU's data privacy regulation] GDPR."
But although Panasonic Avionics and the airlines say the cameras are currently deactivated -- they're not physically covered up and passengers remain worried about hacking.
Kamluk, an expert in cyber-security, says that's a key issue.
"Passengers should understand that this is not about government or airline conspiracy against them," he tells CNN Travel. "I am sure that it's not in the interest of the airlines to spy on their passengers.
"The true risk comes from potential unauthorized access to these devices from a powerful malicious attackers. As far as IFE is connected to the Internet, there is a possibility of remote hack and espionage if such devices can be activated in software."
Passengers also worry their data might be stolen or compromised.
"These may potentially result in VIP passengers' communications being eavesdropped, passport data being photographed while filling customs declarations, entering of secret PIN code or password to unlock user's devices may be recorded on video," says Kamluk.
"You may say that regular CCTV poses similar risk, but when the camera with mic is very close and just in front of you, the quality of such shots, video and audio recording makes [a] big difference."
Aviation consultant Peter Lemme told CNN Travel that such fears were not unfounded and airlines needed to listen.
"The public response would suggest cameras facing passengers is a toxic undertaking," says Lemme. "Privacy seems to be the greatest concern, and that gets to spying and publication.
"The upside of an IFE system that recognizes a passenger has fallen asleep, pauses the movie, darkens the screen and substitutes calming music is balanced against the concern that somehow the camera will take pictures of the person that will embarrass them or will be distributed improperly."
"Trust is the variable between business and customer. It is hard to earn and easy to lose. Airlines depend on passengers trusting they will hold their traveling details private. There is no upside for an airline to endanger trust, but there is much downside."
Many internet users tape stickers over their computer's camera as a means of ensuring privacy. Should airlines physically cover the cameras, to reassure passengers?
Lemme thinks so.
"There must be no chance of surveillance unless the passenger agrees to it. Does this mean a physical cover plate -- I think yes. I don't know any other way that would [be] compelling to everyone," he says.
"One good strategy is to give passengers a little bit more of control on their privacy level," he says. "The manufacturers could do one simple hardware switch to enable/disable all questionable sensors such as cameras and mics."