me_irl

Ads can mean many things. It could be short for something (for example Active Directory Settings). I remember getting something legitimate blocked like 10 years ago but nothing in recent years so I imagine the detection got better at dealing with that.

Step one is you don't refuse files from the server, and try to answer as if you have them when asked in js. But the current actual methods and arms race is happening by comparing computed results, how your page is rendered according to your own browser when probed, vs how the detection code expects it rendered. Adblockers do things like lie, or inject things that can look close enough to ads that you pass the tests. You can see how detection works and try to sidestep what it does by looking at libraries like these https://github.com/sitexw/FuckAdBlock

This one in particular will probably just not run in uBlock out of the box so this one's pretty easy to sidestep. But you can stuff code like this obscured in your site and another piece of code that checks that it hasn't been removed. It's pretty difficult for website develops to win this fight, since ultimately they're letting us download and render their pages with fairly transparent technology.

In uBlock Origin, you can add filters.

Either those you download from the internet, or you can go add items yourself by clicking the uBlock Origin icon and selecting the "item picker".

Then just click on the item you want to block.

There are more advanced ways to block stuff, like based upon content. I used this to block all the "suggested for you" posts on Facebook.