Firearms, knives, and illegal substances are unsurprisingly prohibited at the 2012 London Olympics, but here's one you might not expect: unsanctioned portable Wi-Fi hotspots. Ryan Seacrest Productions' Sadao Turner tweeted an image of a member of the Olympics' "Wi-Fi Police," carrying an absurdly large frequency detection device that ironically screams "free hotspot this way." Wireless interference is part of the concern, but it stands to reason that Olympics partner BT — which runs some 1,500 paid hotspots at the event — is looking to keep revenues up as well. Either way, Wi-Fi peddlers should keep an eye out for the enforcers should they wish to keep their signal active.