The European Parliament has adopted a controversial bill that will give the United States access to personal information about airline passengers.
MEPs agreed by 409 votes to 226 to let the US Department of Homeland Security see data on the Passenger Name Record (PNR), under strict controls.
Supporters say this is a vital step in the fight against terrorism.
But some fear information could be used for other unspecified purposes which could affect civil rights.
The information includes names, addresses, credit card and phone numbers, but may also include sensitive data on an individual's ethnic origin, meal choices, health, political views and sex life.
The US authorities say they will "employ automated systems to filter and mask out sensitive data from PNR".
The agreement applies to airlines operating flights between EU countries and the US.
It covers not only European airlines but also any carriers that are "incorporated or storing data" in the EU and operating flights to or from the US.
The deal says PNR data will be used exclusively to combat terrorism or fund-raising for terrorism, as well as trans-national crimes that incur a jail sentence of three years or more.
Although airlines already collect a great many details on passengers, from phone and credit card numbers to meal preferences and medical conditions, now they will transfer that data to the US Department of Homeland Security.
Privacy concernsThe BBC's Imogen Foulkes in Strasbourg says many questions remain about how the information will be used, how long the US will keep it, and who else might have access to it.
Some MEPs fear the deal sets a precedent and ask how the EU would respond if China or Russia asked for the same information, our correspondent says.
The deal says any passengers who believe their data has been used wrongly will have access to US justice to seek redress.
The leader of the conservative group of MEPs, Martin Callanan, backed the bill.
"We've seen numerous attempts to blow up transatlantic airliners in recent years, how stupid would we look if we had the chance to stop one of these things, and one of the terrorists actually got through, so we have to err on the side of public safety on this," he said.
But other MEPs say the proposals leave too many unanswered questions, such as how will the US use this information, how long will it keep the data and who will have access to it?
Dutch Liberal-Democrat MEP Sophie in 't Veld was on the committee that drafted the proposals but voted against the bill.
"This agreement unfortunately does not meet our standards, it does not protect the rights of European citizens, they do not have adequate means of legal redress, and therefore unfortunately we cannot adopt this agreement," she said.
The US ambassador to the EU, William E Kennard, hailed the vote, saying it showed a joint EU-US "commitment to the security of the travelling public".
He said it would "provide legal certainty for airlines and assure travellers that their privacy will be respected".
According to British Conservative MEP Timothy Kirkhope, PNR data was "instrumental" in capturing collaborators of the 7 July 2005 London bombers and the 2008 Mumbai terror attackers.
He said PNR data had also "led to the capture of dozens of murderers, paedophiles and rapists" and "95% of all drug captures in Belgium and 85% in Sweden are caught using PNR data".
>>>