It's been nearly a year since the bot situation in Team Fortress 2 escalated to a point where Valve had to get involved, but despite those efforts to curb the infestation, the problem has not gone away. Along with bots using game-ruining hacks, bots in casual servers are continuing to use racist usernames and spam voice chat with loud noises. There are now reports that bots are increasingly being used to advertise bots and bot immunity - and disturbingly, that some claim to offer links to child sexual abuse images.
Eurogamer has seen screenshots of bots using Team Fortress 2's chat function to advertise links to ecommerce platforms such as Shoppy, where bot hosters have found ways to monetise their disruptive efforts. Along with offering the option to rent bots, stores are offering the option to purchase "bot immunity" to allow the player to be ignored by that particular brand of bots. It's basically a virtual protection racket.
This seems to have been an issue for the past few months, as posts about bot immunity first appeared three months ago, but reports of these adverts are continue to pop up on Reddit.