What you just described is actually a web beacon [1], in which case the one that embed the URL is the user (and not the one who load the <img>). Web beacon can

What you just described is actually a web beacon [1], in which case the one that embed the URL is the user (and not the one who load the <img>). Web beacon can be used to implement useful thing like visitor counter service [2]. [1]: https://en.wikipedia.org/wiki/Web_beacon https://en.wikipedia.org/wiki/Web_beacon [2]: https://www.hitwebcounter.com/ https://www.hitwebcounter.com/