I run my own DNS caching server at home. Two of them, one primary, one backup. I have my own home network in it, and then it caches the rest of the Internet. For a long time, I have also used zones to over-ride some domains and point them to 127.0.0.1. One of these is doubleclick.net. It's pretty good, because any calls to doubleclick.net will result in 127.0.0.1, and any attempt at connection will fail. This has worked really well for years, and I have eight really awful domain names set like this. It avoids some tracking, lots of ads, and reduces network traffic.
Recently, I've been experimenting with cord-cutting and have been subscribing to streaming services for TV. I have a Roku and an Apple TV. I installed the PBS app on the Roku, but every time I went to view a program, the app just crashed. Google soon gave me the reason - I am trapping doubleclick.net in DNS and PBS depends on it and will crash. I altered my DNS server and allowed doubleclick.net just so I could watch PBS. I watched The Great American Read, about books.
But holy hell, did that open up a mess of garbage. My iPad started to show ads where they had never been before. Web browsing got ugly. Doubleclick.net opens up to so much garbage. I had enough tonight and blocked it again. PBS no longer works, but I can live with that if it lets me shut out all those ads.
I have installed an antenna and can pick up local digital free-to-air TV and that gives me four channels of WHRO which effectively gives me most PBS, so I'm not missing out on too much.