Looks to me like there is a major differene between the Yes Men's actions and the tounge in cheeck approach of the ZKM site. The ZKM site is a self-referential statement (like a TV talk show with talk show hosts discusscing talk shows and enjoying it throroughly to show that talk shows and their hosts are really great). The Yes Men go beyond the system of "fractal regressum ad infinitum". And Robbin Murphy's remark that ?hilip ?ocock/?eter weibel might indicate that they are not really the curators - I do not believe that is correct, since all the other people listed are ZKM staff working under Peter Weibel. So all the little pointers are "tongue in cheek" and "cute" and pointing to all of us from a superior point of view as we might get upset about what seemingly was done. And then one could say; See, this is exactly the positive outcome of our little trick here - you all started to discuss the real issues because we got you startled. 
So, yes, one can seriously discuss the quality of this website, how was it done, are means and methods and goals in sync etc. And one can start the ethical discussion and the curatorial - which I think is always good, again especially becasue the relation bewteen author and public domain seems to be quite more confused in the new media arts world than e.g. in the "regular digital domain". Maybe one can learn from their perspective and their concept fo "respect". And I just watched the old 1984 movie again (shot in 1984) and it is especially true in the digital age that the collage of past, present and future serves those who are in power. and those who are in power determine past, present, and  the future, e.g. what and how the web archives "remember" the past.
 
So from an artistic point of view I find the web project at ZKM "cute" (with all the negative implications). And the ethical discussion - as Sarah pointed out - has nothing to do with that project. I personally am sorry about these kind of traps being set up under the flags of large institutions and "art". I do not see them as necessary and would prefer to see them executed (!) by individuals or small groups as undermining activities. 
 
I find the ethical issue more with how actually large institutions reflect their own activities, the correlation between power and money and influence (in German "Verfuegungsgewalt" - a beautiful term in the sense that it is extremely transparent and reveiling). And please let me add that I was one of the "founding generation" of ZKM and worked there for 13 years to get it off and running -  and that I am currently working on setting up a similar large institution here in the US. So, again, for me there is the discussion going on here on the consequences of hacking history in the digital space (no cut and past any more with glue liek in 1984) and how it relates to art and activism and what have you or what have you not. And then the other issue if large instiutions can behave like underground guerillas or if that actually perverts the actual point which was tried to be made. And this is another real curatorial question - how does the position your institution has in the context of the segment of the world you are active in reflect on the work you may/can/should/want to show and work for.
 
Johannes Goebel
 
P.S. Before this whole discussion on this list  started, I received ZKM's news letter. In it was an announcement of this project in such awfull curator-speak, that - for the first time in my life - I felt compelled to write to the press department at ZKM to steam off on how anyone could write such horrible stuff and expect people to still want to visit the exhibition. And let me reassure you that the curator-speak of this notice was just only 5 degrees more than the usual level of such announcements (which for my taste are already mostly undigestable). So it was absolutely not clear that this was to be a joke - but maybe it was not and it is only my limitation and narcicm that is actually the goal of this project to make me aware of that did not get it?