1. I would say that the use of (CC) licensed photo with the NC clause (noncommercial) on @in_focus which has ads is, in fact, commercial use.

    @Waltarrrrr Do you know one of your photos was used on the @TheAtlantic by @in_focus?

    http://www.theatlantic.com/infocus/2012/08/curiosity-lands-on-mars/100348/