Nuts
If anyone from the general public had any idea what they are talking about when it comes to RFID tags, I'd be highly surprised.
An RFID tag will be as easy to remove from a garment as a price tag or bar code.
Any speculation that a manufacturer would embed such tags in the fabric of a garment really has no basis in reality - it'd be commercial suicide. As for carrying scanners around to scan passers by and find find out whether passers-by are wearing Agent Provocateur undies.... ROFL (if it wasn't so sad).