Officer Barbara believes Mark is hacking into patrons' computers through free, wireless internet coffee shops. Specifically, she sees Mark travel from coffee shop to coffee shop, where he sits in the back, wearing a baseball cap and sunglasses. Officer Barbara stops Mark at a coffee shop and frisks him, whereupon she seizes an item from his pocket. The item turns out to be a technological device that helps Mark hack into computers. Explain whether the stop and frisk are permitted under the stop and frisk exception.