Probable cause for whom? A store proprietor or a peace officer?
Both. FS 812.015
(3)(a) A law enforcement officer, a merchant, a farmer, or a transit agency's employee or agent, who has probable cause to believe that a retail theft, farm theft, a transit fare evasion, or trespass, or unlawful use or attempted use of any antishoplifting or inventory control device countermeasure, has been committed by a person and, in the case of retail or farm theft, that the property can be recovered by taking the offender into custody may, for the purpose of attempting to effect such recovery or for prosecution, take the offender into custody and detain the offender in a reasonable manner for a reasonable length of time. In the case of a farmer, taking into custody shall be effectuated only on property owned or leased by the farmer. In the event the merchant, merchant's employee, farmer, or a transit agency's employee or agent takes the person into custody, a law enforcement officer shall be called to the scene immediately after the person has been taken into custody.[emphasis added]Note also in the definition part of that statute(b) The activation of an antishoplifting or inventory control device as a result of a person exiting an establishment or a protected area within an establishment shall constitute reasonable cause for the detention of the person so exiting by the owner or operator of the establishment or by an agent or employee of the owner or operator, provided sufficient notice has been posted to advise the patrons that such a device is being utilized. Each such detention shall be made only in a reasonable manner and only for a reasonable period of time sufficient for any inquiry into the circumstances surrounding the activation of the device.
(c) The taking into custody and detention by a law enforcement officer, merchant, merchant's employee, farmer, or a transit agency's employee or agent, if done in compliance with all the requirements of this subsection, shall not render such law enforcement officer, merchant, merchant's employee, farmer, or a transit agency's employee or agent, criminally or civilly liable for false arrest, false imprisonment, or unlawful detention.
(1)(h) "Antishoplifting or inventory control device" means a mechanism or other device designed and operated for the purpose of detecting the removal from a mercantile establishment or similar enclosure, or from a protected area within such an enclosure, of specially marked or tagged merchandise. The term includes any electronic or digital imaging or any video recording or other film used for security purposes and the cash register tape or other record made of the register receipt.thus, even a video tape of you doing something innocent yet suspicious looking is sufficient to stop you and you have little or no recourse.