Are those "free" as in "public domain" respectively "CC-BY(-SA)"? Or are they just "free" as in "freeware, please don't touch"?
"You can freely use it for both your private and commercial projects, including software, online services, templates and themes. The set may not be resold, sublicensed or rented. The set may not be offered for free downloading from websites other than SmashingMagazine.com. Please link to the article in which this freebie was released if you want to spread the word."
According to the previous tight conditions, it's hard to believe that the author really wants those icons to be widespread.