<!-- <rdf:RDF xmlns="http://web.resource.org/cc/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"> An alternative to "bluespamming" Bluetooth marketing is raising concerns since it is basically based on an opt-out, rather than an opt-in principle. Since the technology offers interesting opport