Though it be said a million times, it bears a million more repetitions:
Error has no rights.
I once saw a poster in a subway station in NYC depicting two fαɢɢօts kissing. I didn't hesitate to tear it down and rip it to shreds before consigning it to the nearest garbage can. I'll brook no legalistic claptrap about "property rights" here. I defy any Catholic to condemn the "evil" in my act of "vandalism" over and against the genuine evil caused by innocent children having to see that disgusting piece of propaganda for promoting that most abominable affront to Almighty God.
Let's let St. Francis Xavier have his say on the matter:
"These children, I trust heartily, by the grace of God, will be much better than their fathers. They show an ardent love for the Divine law, and an extraordinary zeal for learning our holy religion and imparting it to others. Their hatred for idolatry is marvellous.... Whenever I hear of any act of idolatrous worship, I go to the place with a large band of these children, who very soon load the devil with a greater amount of insult and abuse than he has lately received of honor and worship from their parents, relations, and acquaintances. The children run at the idols, upset them, dash them down, break them to pieces, spit on them, trample on them, kick them about, and in short heap on them every possible outrage."