Take my opinion with the grain of salt.
I think the shirt can be tongue in cheek funny (but my humor is weird like that). I just don't know who is behind it, whether some gang claiming that they're Orthodox created it or some dorky guy in his mother's basement. I actually would buy that shirt and wear it around the house -- not in public if I didn't know who was behind it or created it.
No, it's not funny at all. This slogan, as well as its "sister"-slogan, "Russia for Russians," is officially put in the list of extremist slogans by the Ministry of Justice of the Russian Federation (http://lenta.ru/news/2011/05/16/slogan/
I can't recall at the moment, who was the person who started making these t-shirts (maybe later in the day I will obtain the information from my Russian Facebook friends). All I know is that the force, the organization behind it is clearly Fascist, ultimately xenophobic Russian chauvinist group. The people who buy these t-shirts hate everything that is beyond their chimpanzee "brain" - the West, the USA (especially), NATO, Jews, Free Masons, homosexuals, Blacks, Catholics, non-ethnic Russian citizens of their country, Chechens, Georgians, Armenians, Asians - you name it. Their "Orthodoxy" lives, is sustained, fed, exclusively by hate, which spreads also on those Russian Orthodox whom they hate for, allegedly, being ready to compromise with all these "Sodomite-Liberal-proWestern-nonRussian forces of evil." The latter include anyone who happens to say anything they don't like, for example, Fr. Deacon Andrei Kuraev (who used to be a personal favorite of the previous Patriarch of Moscow, +ALEXIUS II (Ridiger), and who actually is a rabid xenophobe and Russian chauvinist, just not passionate enough for these extremists), or even the present Patriarch of Moscow, +KIRILL (Gundyaev).
These people are a disease, a plague, an ulcer, a cancer. I cannot even begin to describe how stupid, ugly, sick, and dangerous they are. They discredit Orthodoxy like nothing else. "Thanks" to them, a term has been popularized in Russia and in Ukraine: "diagnosis, Orthodoxy of the brain" ("православиe головного мозга").