orders ignored in order

I hate it when T-shirts like these clash with reality:

Lest anyone think that the above is the company uniform Joey Vento issues to the employees of Geno’s Steaks, it’s actually associated with the rock group Clash. From the above website:

Our best seller! This one is for the Clash fans. A faithful reproduction of the enigmatic sticker Joe Strummer sported on his famous Telecaster guitar.

Sure enough, Joe Strummer’s guitar did sport an “IGNORE ALIEN ORDERS” sticker. (Picture here.) But where did he get it?
The first use of the slogan that I remember was by the Grateful Dead during the band’s early 70s “hypnocracy” era.
Perhaps because of braincell attrition, there doesn’t seem to be much discussion so that I can pinpoint with accuracy the Grateful Dead origin of the slogan. After considerable diligence, I was able to find a small piece of archaeological evidence — in the form of this “Wake of the Flood” matchbook cover.

Wake of the Flood was released in 1973, Joe Strummer chose his name in 1975, and formed the Clash in 1976.
But obviously, the big question today is whether it might constitute discrimination to wear the above T-shirt at all — much less follow its message by actually ignoring alien orders.
Are there any implications as to intentionality?
(T-shirts, of course, can have a diversity of implications. . .)