[krageon]

There's a whole slew of arguments that could be made here, but let's keep it simple: Providing anyone with information about me should be a voluntary act. If I choose not to do so, it is none of your or anyone else's business why I do not want to.

This choice is not available in the case of UTM's, at least not in a transparent way that doesn't involve manually stripping them from every URL you click (which is sensitive to user error).