CNN (CNN) Those Black Friday and Cyber Monday super sales are not only a boon for your bank account, but may also reap serious rewards for cyber criminals intent on causing harm, according to the FBI.

In a pre-holiday message to consumers, an FBI field office is warning that " smart TVs " -- televisions equipped with internet streaming and facial recognition capabilities -- may be vulnerable to intrusion.

In addition to outlining how new advanced technological features risk allowing television manufacturers and app developers to snoop on consumers, the bureau says malicious cyber actors can also take control of unsecured smart TVs and potentially wreak havoc on unsuspecting owners.

"Next-gen smart TVs and devices run complex software, have Internet connections, and often have integrated sensors like microphones," says Matt Tait, cybersecurity expert and former analyst at GCHQ, the British signals intelligence service. "These features enable things like internet streaming services and voice-commands, but can unfortunately be subverted by hackers if the device gets compromised."

"At the low end of the risk spectrum, they can change channels, play with the volume, and show your kids inappropriate videos," the FBI warning states. "In a worst-case scenario, they can turn on your bedroom TV's camera and microphone and silently cyberstalk you."

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