I agree with Gary - yell "THIEF" at the top of your lungs and basically anyone who appears to be getting out in a hurry will probably be tackled and held for questioning by any breeder in the vacinity.
I also agree with Cruciform - had I witnessed this taking place, the only warning would be my elbow right in the back of their neck. I think thieves are among the LOWEST forms of slime on this planet. I only hope that when they find these jackasses, they find them with the tortoises in good health.
- Ken LePage