What license are these logos being released under? The alternative set specifically states CC-BY 3.0... but the main set, as far as I can tell only have the implied licence granted by being allowed to use them to advertise the license.
That was my first question. The attribution requirement for the alternative logos is quite a drag. I really wouldn't bother with a logo that requires credit like that.
It might not be license-compliant, but if I were to ever use these logos, I would claim to satisfy the attribution requirement through comments in the page source. After all if you write a CLI tool that links GPL stuff you don't have to mess up your output with license crap. Those who want to know will read the source.
Isn't attribution solved by linking at their page with the explanation of the logos?
It seems to make more sense for the logo itself to link to the explanation of the actual license. (e.g. http://www.gnu.org/licenses/agpl-3.0.en.html ) I agree with parent posts that it is a confusing distraction to have some other link also present on the page. If GNU wanted to put such links on their license pages, they could. Now they just have a logo and a link to TFA.