Travel companies were hit by one data breach after another last year — firms including Marriott, British Airways, Delta Air Lines and the travel booking site Orbitz.Marriott estimates that as a result of its breach — in which the reservation database of Starwood-branded hotels in its portfolio was hacked — 383 million guest records could have been affected and 5.25 million unencrypted passport numbers were possibly compromised. And experts expect breaches in the travel sector will continue.“Travel companies are a prime target of cyberthefts” because they have “highly sensitive, personally identifiable information,” said Eva Velasquez, chief executive of the Identity Theft Resource Center, a national nonprofit organization…