The nice thing about free speech is how it tends to allow speakers to parade their all-consuming ignorance with all the self-consciousness of a streaker at a rugby game.

Something on that level happened last week when a genius decided to exercise his freedom of expression and deface a sign, put up by the Freedom from Religion Foundation, that urged passersby to keep religion out of government.

The budding spray-paint artiste covered over the word “religion” on the billboard with another word of four letters, that number presumably chosen to reflect the square of the artiste’s IQ.

Since it’s unlikely there’s a groundswell in the Grand Valley against the cancer sticks smoked by Cockney nicotine fiends, it’s probable that the four-letter word referred to men who are sexually attracted to the same sex.

It might be nice to see some variant of handwriting analysis used to identify the miscreant, but the fact is that he (or, possibly but not very likely, she) rendered the artwork in question while in a hallucinogenic- or alcohol-induced haze.

For the record, that’s pure speculation.

But that’s the nice thing about this free- speech thing: It virtually guarantees that the droning menaces who shuffle unnoticed among us eventually will cast off the camouflage of everyday, relatively quiet stupidity and gloriously self identify in a gauche burst of spray paint.

Such is the case here.

It’s worth noting that a previous column I wrote on the subject of that very billboard took issue with the whole idea of keeping religion out of government. That column elicited a response from the usual suspects eager to demonstrate a pronounced, even practiced, ability to miss the point.

Still, the exchange was civil and steered well clear of vandalism.

Passing over without comment the possibility that a reversal of circumstances could very well garner a grant from the National Endowment for the Arts and sackloads of fawning publicity, we should consider what exactly ought to happen now.

Sadly, much of the point that the billboard made was underscored by the specimen of homo moronicus who tarnished it. To be sure, there are those who would cloak prejudice in religious garments and call it God’s work.

There also are those who would muzzle dissent by calling it hate speech.

In this case, the former seems to be at play.

Call it a social contract if you like, but there’s something of an unspoken agreement implicit in the freedom of speech.

The atheists paid for a billboard. Had they chosen to do so with cash, the bills would bear the words “In God We Trust.”

In any case, they purchased a property right that was violated, ostensibly in the name of the people who disagree with them.

At least it’s easy for the atheists to blame the opposition.

Appearances might be mere veneer, but they do count for something.

One can’t very well claim to support free speech, private property and all that and fail to condemn those who would violate either.

Spray painting the billboard amounts to theft.

Condemnation, of course, is cheap.

Anyone with a spray can, the cover of darkness and a shot of courage can manage that, as homo moronicus has indelibly demonstrated.

If you want to stand up for free speech, property rights and the stuff at issue, send a few bucks to the Freedom from Religion Foundation, P.O. Box 750, Madison, Wisc., 53701. Enclose a note saying that it’s intended as recompense for the work of some halfwit in Grand Junction stealing their sign.

They’ll be shocked. Really.