What are ad blockers?

Wherever there is offense, there is also defense. To fight back against sites full of ads, most modern web browsers allow users to install ad blocking extensions. These extensions try to detect and block content from sites known to serve advertising content. Ad blockers can make browsing the web a much more enjoyable experience. But as more users have installed ad blockers, sites have begun to fight back by either refusing service to or complaining about users with ad blocking software installed. This reflects an economic reality of the modern internet-​ads are important source of revenue for many sites that provide free content.
Credits: Talking: Geoffrey Challen (Assistant Professor, Computer Science and Engineering, University at Buffalo). Producing: Greg Bunyea (Undergraduate, Computer Science and Engineering, University at Buffalo).
Part of the www.internet-class.org online internet course. A blue Systems Research Group (www.bluegroup.systems) production.