[reaperducer]

for the express[ed] purpose

This doesn't mean what you think it means. What you wrote means that web sites put text on their pages stating, "We're proxying our ads so you can't block them, nanny nanny boo boo!"

You probably mean "specific" purpose.

More to the point, this isn't new. We were doing this on web sites at least as far back as the early 2000's.

[cshimmin]

Uh, no GP's usage was fine. Take Collins dictionary: "If you refer to an express intention or purpose, you are emphasizing that it is a deliberate and specific one that you have before you do something".

Perhaps you are thinking of the term "express written consent", but there it's the word "written" that means it was, well, written.

[minitech]

Yeah, I guess if you insert the incorrect [ed], it becomes incorrect.