Locking down those credit cards while globe-trotting is always a chief concern. Today at Mobile World Congress, MasterCard and Syniverse announced a joint effort to ease the fears of travelers. The pair is working on a pilot program that will only allow card-based transactions when a user's mobile device is in a specific location. This means that if you (and your phone) are in Barcelona and someone tries to use your card in Madrid, the purchase will be declined. In addition to the security measures, users will have the option of procuring prepaid data packages on said handset upon arrival to insure that the requisite GPS works. Of course, the setup is in testing at the moment, so there's no clear indication when or if the geolocation option will become available.