Some sites recommend Adblock Plus (or just "an ad blocker," for which Adblock Plus is often the first search result) as a privacy or security tool. But Adblock Plus uses deceptive "dark patterns" to avoid offering real privacy or security to users.
Please do not recommend either Adblock Plus or "an ad blocker" to users who are concerned about web privacy or security.
Adblock Plus runs a paid whitelisting program called "Acceptable Ads". The "Acceptable" criteria include no rules against common user privacy and security concerns, such as malvertising and PII misuse. And configuring Adblock Plus to actually provide tracking protection is complicated.
Go to "Filter Preferences" in the ABP menu.
Click "Add filter subscription"
No privacy lists appear on the main drop-down. You will have to hunt for them behind "Add a different subscription".
Scroll down and eventually find the "EasyPrivacy" entry from a long list.
Click "Add subscription".
So far, it's time-consuming and deliberately complicated, but not deceptive. (Keep this in mind when Adblock Plus proponents talk about how users are mad about annoying ads but don't mind tracking. If users don't mind tracking, why did Adblock Plus make it so hard to make the choice?)
Turning on a privacy list is enough of a maze to discourage users, but not deceptive deceptive. That's found in another place.
Now for the deceptive part.
Even after you go through the above five-step (!) process to find and turn on "EasyPrivacy", you're still not protected. This is not clear unless you read the fine print. The "Acceptable Ads" paid whitelisting program actually overrides your explicit EasyPrivacy choice, to allow tracking by Google, Criteo, and other companies.
In order to make your tracking protection choice take effect, you also have to turn off "Acceptable Ads" using a different option, which is labeled "Allow some non-intrusive advertising."
To really block trackers, un-check a box with a label that says nothing about trackers at all.
The checkbox is not even labeled "Acceptable Ads," maybe just in case a user has heard of "Acceptable Ads" and knows about the controversial paid whitelisting program.
What to do instead
The good news is that alternatives are available.
If you maintain a directory of web software, please do not list Adblock Plus in a privacy or security category.