> > I think this has the same flaw as the recent Google invention of
> > an attribute ...
> 
> Any pointers to  this subject?

http://lists.w3.org/Archives/Public/www-html/2005Jan/0037.html  

is the first archived article in the thread.

Google actually set an attribute on their links, but one of the
criticisms is that it is a specific command to the technology,
rather than descriptive, and the other is that what they really
should be signalling is that the whole of the third party blog 
comment is unsafe, not just that the links are unsafe.