Wouldn’t it be nice if you could see how many of your visitors have adblock plus installed? So then you can see if it’s worth to place ads on your site or if you have to look for other ways to make money with your site. For some info on how to detect adblock, search google for “how to detect adblock” (the forum didn’t allow me to post links)
Here you have an example of how to detect adblock plus: Detect Adblock Users on a WordPress Blog – Joe Riggs Bloggs
If the user has AdblockPlus, chances are he/she is blocking Piwik’s tracking code, so you wouldn’t be able to track it, even if you could detect it.
Can’t you just change piwik.php and piwik.js to something else, more unique, to get around adblock?
Sure. Use the /js/ proxy.