Orders like these are normally written out by judges that are completely oblivious to how reality works. Adding to that the fact that people with power know they tend to get things their way in Brazil, and that the government is all-powerful, I'm quite sure this guy just assumed he could change the laws of the universe with a stroke of his pen.
It's wonderful to have a succinct word for a concept like that; I wish there were such a word in English. Do you have any background information about the origins and meaning of this word?
Caneta means pen in portuguese. Canetada, although not a dictionary word, means the act of swiftly using a pen to show "who is the boss" - signing an impromptu decree or order of questionable legitimacy for example.
Portuguese, maybe especially Brazilian Portuguese, has a good number of made-up words that can be created by simply adding certain suffixes to common words. They might not be in the dictionary; that'd grow its number of words exponentially I assume. But they're widely used and understood. In this case, "-ada" is basically added to words when something is used indiscriminately, normally by hitting something or someone, or throwing it.
Whacking someone with a wooden stick ("pau") is a "paulada". Kicking a ball ("bola") on someone is a "bolada". Poking someone with a pin ("alfinete") is a "alfinetada".
Therefore, using a pen ("caneta") indiscriminately becomes a "canetada".
The same word would be used if you threw the pen at someone's head, so there's that.
