Public domain issue for graphic design project?

[Respectedhorse698]

Of course trademarked logos are not in the public domain.

Just because you're not making a profit, it is not "fine" to use such work. If the guidelines specifically prohibit such things, you must not use them.

Simply manufacture "fake" logos which vaguely resemble them, with the explanation that these logos represent links to common social networking features, such as twitter and facebook.