A backlash from travelers concerned about privacy is prompting airlines to cover small cameras in the back of customers’ seats. United Airlines and Delta Air Lines have both responded to the concerns, with United placing stickers over the lenses. The cameras come as part of the seatback entertainment system and are installed by the manufacturer with the idea they could one day be used for purposes such as video conferencing. READ: Out with the gold as United reveals new livery. United said in a statement that the cameras had never been activated and the airline had no plans to use them in the future. “However, we took the additional step to cover the cameras,’’ it said. Delta also said the cameras were not in use but said it was important to reassure customers. “A limited number of Delta in-flight entertainment screens have non-functional cameras, included by the manufacturer," the airline said. "Though Delta does not have plans to install the necessary software to use them, we have added covers as a visible way to reassure customers." Other airlines on which the cameras have been spotted include Singapore Airlines and American Airlines . All of them also deny using them to monitor passengers and IFE manufacturer Panasonic Aviation described the privacy fears as misplaced. However, that didn’t stop two US legislators proposing legislation to ban the potential spy devices. Senators Jeff Merkley and John Kennedy wrote to airlines expressing concerns that in-flight cameras could monitor passengers while they sleep, eat or have private conversations. “Further, in light of data breaches that have impacted many major airlines, we have misgivings that cameras or sensors may not employ the necessary security measures to prevent them from being targeted by cybercriminals," they said. The Senators’ bipartisan Passenger Privacy Protection Act seeks to prevent future IFE’s from having an embedded camera or microphone and proposes that existing cameras should be removed, permanently disabled or covered.