Hi enkidu1947,

There are many websites that are coded in a way so that if certain parts of the website do not load, there's secondary content to be loaded in.

Generally speaking, Javascript is the web language that is being blocked (in cases of Ad Block Pro, you can block the Frame and/or the link it comes from).

That is the detection process. If the script is being blocked, how it was programmed will determine the outcome. Otherwise if the script is being blocked and nothing is showing (no alerts), there wasn't a secondary measure programmed into place.

I should also mention that this type of scenario doesn't rely on the OS you're running, just the browser and how you interact with the website in question.

To add on to the above:

There are a number of reasons that a page may detect that ads are not loading, even if you haven't installed Adblock Plus, uBlock, or another ad-specific extension. For example:

• Firefox's built-in Tracking Protection feature may trigger this message. It is enabled by default when you use private browsing. You can read more about that in this article: What happened to Tracking Protection?.

• I use the NoScript extension, and sites sometimes tell me that I use an ad blocker because even though it is a script blocker, in both cases, the result is the same: ads are not loading where/when the site expects them to load.

jscher2000 said

.........

• I use the NoScript extension, and sites sometimes tell me that I use an ad blocker because even though it is a script blocker, in both cases, the result is the same: ads are not loading where/when the site expects them to load.

+1, i love NoScript, sometimes it is a little aggressive but it is the "best cop on the web".

thanks