It’s not clear to me what the license is. Given that there are large number of corporate brand icons, I assume that these were just vacuumed up from the web, and there is no way to know if you have the legal right to use them for your own purposes.

There is a disclaimer that the icons are free to download based on the creators copyright restrictions. So presumably because these icons existed somewhere on the web, you have the right to download them onto your computer, but not use them yourself.

Until the licensing issue is clarified, I would stay away.