The Federal Communications Commission issued an enforcement advisory Tuesday saying that blocking an individual's personal Wi-Fi hotspot is illegal.

Any company that attempts to block a Wi-Fi hotspot willfully or with malicious intent will face the possibility of being leveled with "substantial monetary penalties," the FCC said in a statement on Tuesday. The government agency specifically mentioned hotels and convention centers, which it says, have been engaging in the blockade of personal Wi-Fi hotspots.

The announcement comes just days after hotel chain Marriott announced that it would no longer block Wi-Fi hotspots. Last year, the hotel chain used a Wi-Fi deauthentication tool at its Gaylord Opryland location to block Internet access to hotel guests who wanted to use their personal Wi-Fi hotspots on their smartphones, tablets, or standalone devices. After the FCC learned of the move, the agency fined Marriott $600,000.

Marriott said after it was hit with the fine that it believed the Opryland hotel was acting lawfully. The company told CNN in a statement that the hotel's stance on banning personal hotspots was designed to protect its visitors "from rogue wireless hot spots that can cause degraded service, insidious cyberattacks and identity theft."

Marriott's argument centers on the belief that personal devices that establish hotspots -- everything from wireless MiFi devices to smartphones -- can create a security issue. Unwitting targets could connect to those networks and potentially fall victim to malicious hackers looking to steal data. The company has said that by blocking those networks and forcing customers to pay for access to the hotel network, it's providing security that customers desire.

The FCC said in its statement on Tuesday, however, that Marriott admitted to the agency that those who were using the personal hotspots "did not pose a security threat."

Still, Marriott isn't alone in its stance. This past summer, a group of hotel chains issued a request to the FCC, asking for permission to block personal hotspots based on the group's belief that personal hotspots could cause undue security issues in hotels. Many major technology companies -- including Microsoft and Google -- have argued that blocking personal hotspots is wrong. The wireless industry organization CTIA also has criticized the hotels, saying that hotel guests have the right to use their personal cellular networks whenever they'd like.

Critics have also said that blocking Wi-Fi hotspots is a way for hotels to charge for access to their own wireless networks and generate additional revenue off their guests -- something the hotel chains have flatly denied.

However, the FCC said on Tuesday that it has "received several complaints that other Wi-Fi network operators" are blocking hotspots since it fined Marriott, and its Enforcement Bureau is investigating those cases right now.

"Consumers must get what they pay for," FCC chairman Tom Wheeler said in a statement on Tuesday. "The Communications Act prohibits anyone from willfully or maliciously interfering with authorized radio communications, including Wi-Fi. Marriott's request seeking the FCC's blessing to block guests' use of non-Marriott networks is contrary to this basic principle. Protecting consumers from this kind of interference is a priority area for the FCC Enforcement Bureau."

Marriott did not immediately respond to a request for comment.