[L473ncy]

Every form of transmission can be intercepted. It's just how hard it is to intercept.

Over the internet on unsecured connections? Easy as pie.
Unsecure computer terminals (this includes internet cafes, even in suburban/westside areas)? All it takes is a key logger.
Face to face? Well either theres a fly on the wall, or someone is eavesdropping, or the place is bugged.
Telephone? Line tapping etc.
Email? Someone with access (heck even employees with bad intentions can copy and paste the info in that email).

However I'm sorry to hear about bad experiences. At least theres a warning out to watch out for those guys.