A LinkedIn post circulating this week from Michael M. Maurantonio, described as an ad-fraud investigator and media expert and member of the Digital Forensic Research community, has crystallised an inconvenient truth about connected television advertising that industry researchers have been quantifying for years: ads keep running after viewers switch their televisions off, and measurement systems largely do not notice.
The post cuts through the language used to sell CTV inventory. “Premium inventory. Full-screen. 100% completion rates. Sounds perfect,” Maurantonio wrote, before arriving at the problem. According to the post, “the TV is off. The box is still running. Ads are still being counted as ‘viewed.'” The mechanism is straightforward: in many CTV setups, the set-top box or streaming device is the measured unit. The physical television screen – and the human sitting in front of it – is not.
This is not a fringe concern. It sits at the centre of the industry’s most significant measurement debate in 2026, one with a price tag that DoubleVerify has put at approximately $1 billion in annual wasted advertising spending.
The technical explanation: what HDMI-CEC can and cannot do
The post raises HDMI-CEC by name. “In theory, HDMI-CEC can signal whether a TV is on,” Maurantonio wrote. “But in reality? Rarely implemented. Almost never used in measurement logic.”
That assessment is technically accurate. Consumer Electronics Control (CEC) is a feature built into the HDMI standard that allows connected devices to communicate with each other using a single bidirectional wire – specifically, pin 13 on the HDMI connector. According to Wikipedia’s documentation on the standard, CEC is defined in HDMI Specification 1.0 and was updated across subsequent versions including HDMI 1.2, 1.2a, and 1.3a, the last of which added timer and audio commands. The standard supports up to 15 devices communicating on a shared bus.
CEC wiring is, according to the…