Earlier quoted context omitted.
Knowing of UKUSA and Five Eyes, knowing that they share intelligence on parties OUTSIDE the member states , and knowing that they are providing one another with intelligence on each other's citizens and residents are different things. Your Wikipedia article link doesn't directly address this. It points to several other documents though: A 2000 ZDNet article by Duncan Campbell: http://www.zdnet.com/article/echelon-wor…
This article linked from Wikipedia has a Canadian stating that the Brits asked them to monitor British citizens and US lawmakers worrying that it was being used to spy on US citizens: http://www.nytimes.com/library/tech/99/05/cyber/articles/27n... I guess widespread speculation that avoiding domestic surveillance laws is one of the things done with the system isn't the same as knowing that it is going on, but my poin…
From your NY Times article (published May 27, 1999):
Until last Sunday, no government or intelligence agency from the member states had openly admitted to the existence of the UKUSA Agreement or Echelon.
The mutual surveillance / legal evasion possibility appears to be suspected but not demonstrated. Again as with much else, what Snowden's done is to specifically document such activity. Which is of and by itself a material distinction.
European Parliament officials have also expressed concern about the use of Echelon to gather economic intelligence for participating nations.
And:
While few dispute the necessity of a system like Echelon to apprehend foreign spies, drug traffickers and terrorists, many are concerned that the system COULD be abused to collect economic and political information.
(All-caps emphasis added -- minimal HN formatting options have their drawbacks.)
So, I'll maintain that the documentation of such abuse is a New Thing.