Despite past criticism over the practice, Comcast is apparently still delivering pop-up ads to some customers telling them they need a new modem.

“Comcast began injecting 400+ lines of JavaScript code in to pages I requested on the internet so that when the browser renders the web page, the JavaScript generates a pop up trying to up-sell me a new modem,” wrote a Comcast user identified as “bham3dman" in the Comcast Xfinity customer service forum.

“When you call the number in the popup, they’re quick to tell you that you need a new modem, which in my case is not true. I later verified with level-2 support that my modem is perfectly fine and I don’t need to upgrade,” the user added.

Defending the practice, Comcast spokesman Charlie Douglas told Fierce that the company started instituting pop-up notifications in 2009 to let customers know they had viruses on their PCs.

"We also use it to alert customers their device has reached end of life and needs to be replaced," Douglas said. "We do this after having tried all other attempts to reach the customer, which may include email, phone, billing envelope message, and letters. We’re simply trying to make sure the customer is aware they need to replace their device, which they can either rent from us or buy one themselves."

Comcast caught flak from its longtime personal watchdog, The Consumerist, back in January 2016.

At the time, a Comcast executive also defended the practice, saying it wasn’t an attempt to up-sell customers on new modems, but rather an “educational tool” letting them know their modem might not be compatible for long in the emerging DOCSIS 3.1 era.

For its part, Comcast appeared contrite and non-defensive in the forum dialog with unhappy user bham3dman. “That is a failure on our end we'll have to take a look at,” wrote a rep identified as “JL,” responding to bham3dman’s complaint. The perfectly fine modem “should show up in your account when they look at it.”

Added bham3man: “Comcast has my phone office number, my cell for texts, my email, and my home address, yet they choose to molest my requested web pages by injecting hundreds of lines of code. This is not like targeted advertisements when I visit websites with ads (which is perfectly acceptable), this instead is a direct manipulation of the original source code of the website. This is completely unacceptable to me and what’s worse is that Comcast provides no option to opt out of this horrific practice."