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Hoax that grounded US Air jet apparently sparked by Facebook photo

The FBI is looking into motive behind a plane hoax on Thursday that forced a US Airways flight to turn around and head back to the airport in Philadelphia. NBC's Pete Williams reports.

Be careful of what pictures of your ex you put on Facebook.

The boyfriend of Christopher Shell's ex-girlfriend has been charged with making Thursday's hoax phone call that forced a US Airways flight to return to the Philadelphia airport. Shell is the passenger who was removed at gunpoint by federal agents, after a caller falsely claimed he was carrying liquid explosives. 

Kenneth W. Smith, Jr, 26, of Philadelphia, has been charged with making a hoax threat. He'll appear in court at 1:30 p.m. 

The charge carries a maximum of 10 years in prison and up to a $250,000 fine.

Court documents say Smith admitted yesterday that he got up Thursday, walked to a pay phone, and made the call to Philadelphia Airport police. His motive, according to investigators, "was to avenge (Shell's) ex-girlfriend" after Shell posted a compromising picture of her on Facebook.

Shell gave investigators Smith's name after agents asked him who might have made the call. Text messages on Shell's cell phone included "recent hostile messages exchanged" between Shell and his ex about her relationship with Smith, investigators said. Shell told the FBI where to find Smith. 

US Airways Flight 1267 was en route to Dallas-Fort Worth when law enforcement officials were tipped off to a possible suspicious item on board. The jet returned to Philadelphia International shortly before 9 a.m. ET out of a "abundance of caution," an airline spokesman said Thursday.

US Airways rebooked passengers on later flights.

In yet another wrinkle, when Shell arrived to Dallas late Thursday, he was arrested by local police.

He was wanted on several existing warrants in Texas for offenses having nothing to do with the hoax. When he became famous Thursday because of the plane hoax, and police in Texas discovered he was coming their way, they prepared to meet him at the airport and take him into custody on unfinished business.

Federal officials were not certain of the nature of the existing warrants.

The cost of the hoax will cost US Airways "upwards of tens of thousands of dollars in direct and indirect costs," the airline said.

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