While most large incumbent ISPs have rushed head-first into the home security and home automation market, few of those companies have been willing to specify how many users have signed up for such services – suggesting they’re not yet seeing quite the uptake they’d like.

One other threat has now arisen for ISPs looking to be home security experts: lawsuits.

One couple is suing Comcast after the company’s home security platform failed to detect intruders who broke into their home and attempted to sever the arms and legs of their son for fun (seriously).

One month later, police say two men were on a thrill mission to kill. They broke into the Rawats’ basement window and ripped their 18-year-old son from his bed and tortured him, trying to cut off his arm and leg.

"He was full of blood from head to toe, with gashes," said Rawat. "He was in the worst situation possible that a mother wants to see her child in."

But what gnaws at this mother’s memory: the security system, she says, failed them.

The report notes Comcast didn’t install motion detectors on the basement window, promising the couple their home was now "intruder proof."

Like other security firms, Comcast’s contract with security and automation users has users waive all Comcast liability for failed systems, something the couple’s now going to test in court.

Comcast Xfinity Home Security isn’t cheap. In addition to a $30 to $40 per month fee depending on your features, the service features a very steep early termination fee: $770 for the basic service, and $1100 for the Premier service.

You’ll also have to pay an activation fee (which Comcast is waiving for new markets), and an installation charge of between $200 & $300.

Comcast’s security and home automation platform already made the news after a couple recently complained when they realized the service hasn’t been working for seven years.

While the couple is obviously at fault for not paying attention, Comcast’s also at fault for continuing to bill those users that entire period without adequately ensuring the system was working.