People should think twice before clicking on an email that looks like it comes from American Airlines and other major carriers.
Online thieves are using the phony emails to "phish" for personal information -- and even book flights with victims' money.
"Sometimes when you actually click through on these things, the sites that you go to looks just like American," said FareCompare.com's Rick Seaney, who has received hundreds of the phony emails.
The email phishing scheme is taking off right in the middle of the busy summer travel season, when a lot of people would be tempted to click on anything that looks like it comes from an airline.
"This is the first time I've seen a bunch of them related to air travel," Seaney said.
A rash of emails purporting to be from American Airlines, Delta Air Lines and US Airways have all landed in countless inboxes across the country.
The most common claims to be a receipt for a recent preferred seat order, but clicking on the provided link can cost a bundle.
"If they get your loyalty number and your password, you have your credit card already in there -- at least, I do, and I know a lot of people do on American Airlines -- they can starting booking tickets," Seaney said.
Seaney said the crooks typically buy tickets for flights on the next day, before anyone can catch on.
"It's all basically a con game trying to steal money from you," said computer security expert Jeff Farr.
He said the crooks are looking for any personal financial information they can use.
"Delete it if you don't care," he said. "If it rings somehow true -- 'Yes, I was on a flight last week; maybe they messed it up' -- go to the real website. Go log into your account."
Delta is advising customers to change their PIN to access their account.
Farr predicts that another, similar wave of phony emails supposedly sent by major retailers will arrive during the busy back-to-school and holiday shopping seasons.