The FCC isn’t kidding around in going after Wi-Fi blockers: Now it has slapped big electrical contracting company M.C. Dean with a $718,000 fine for blocking consumers’ Wi-Fi connections and has proposed a $25,000 fine for Hilton Worldwide for “apparent obstruction of an investigation” into whether Hilton blocked consumers’ Wi-Fi devices.

Word of this punishment comes on the heels of the FCC hitting Smart City, an ISP for convention centers and hotels, with a $750,000 fine over the summer for kicking users off their hotspots so that they’d have to use Smart City’s more expensive service.

MORE: FCC still has a ton of explaining to do on Wi-Fi blocking rules | How not to get slammed by the FCC

The FCC started the year by issuing a warning that it will no longer tolerate hotels, convention centers or others intentionally interfering with personal Wi-Fi hotspots. This issue grabbed headlines last fall when Marriott International was fined $600K for blocking customer Wi-Fi hotspots, presumably to encourage the guests to pay for pricey Internet access from the hotel.

The whole issue has concerned wireless LAN product vendors and some WLAN managers, who say they aren’t quite sure what they are or aren’t allowed to do nowadays in terms of wireless LAN security and management (See “WiFi blocking debate far from over”).

In its new enforcements, the FCC says that M.C. Dean blocked consumers’ Wi-Fi connections/mobile hotspots at the Baltimore Convention Center on dozens of occasions with the intention of making them pay fees to M.C. Dean for service access. M.C. Dean acknowledged using “Auto Block Mode” on its Wi-Fi system whose manual described this technique as “shoot first, and ask questions later.” It even appears to have blocked Wi-Fi hotspots outside the venue, including in passing vehicles.

“Consumers are tired of being taken advantage of by hotels and convention centers that block their personal Wi-Fi connections,” said Travis LeBlanc, Chief of the FCC’s Enforcement Bureau, in a statement. “This disturbing practice must come to an end. It