The largest threat is a ceramic knife which cannot be detected by a metal detector. Ceramic knives are stronger then regular knives in some situations and absent any metal are completely undetectable.
http://en.wikipedia.org/wiki/Ceramic_knife
The reason why they pat around the groin area is because they fear someone might tape a large ceramic life to their leg. A woman could also have one taped around her breast area.
Another threat is medical devices like walking canes. There are canes out there which have hidden compartments (like the one by Cold Steel) and were specifically designed with fighting in mind.
Although the TSA is not saying, this is their reasoning.
The question is would you rather have your groin groped or the risk of someone popping up with a ceramic fighting knife?
http://en.wikipedia.org/wiki/Ceramic_knife
The reason why they pat around the groin area is because they fear someone might tape a large ceramic life to their leg. A woman could also have one taped around her breast area.
Another threat is medical devices like walking canes. There are canes out there which have hidden compartments (like the one by Cold Steel) and were specifically designed with fighting in mind.
Although the TSA is not saying, this is their reasoning.
The question is would you rather have your groin groped or the risk of someone popping up with a ceramic fighting knife?