Privacy lawyer Gerald Shamash has told the Guardian that the allegations a Virgin Atlantic employee passed on information about eight celebrities is "extremely worrying" and "this could be the tip of the iceberg".
Mr Shamash also said advance knowledge of the whereabouts of celebrities was the "bread and butter" of life as a picture agency or tabloid newspaper.
"Once it has these details, the agency does one or two things: it keeps [the information] to sell it or phones a newspaper to say this person has gone to Los Angeles. It's a symbiotic relationship with newspapers."
More top news
A teenage boy has been stabbed to death in London, the second fatal attack within two days.
A British amateur sailor died this morning after being hit by a sail while taking part in the Clipper Round The World Yacht Race.
Plans for seven-day GP services are "unrealistic" because of a shortage of doctors, the Government has been warned.