It looks like vandals did this if it even happened at all. This is hardly news.
Me and my band of outlaws in college did this kind of sh__ all the time.
Some of our greatest hits were......
"Free Beer" at a Baptist Church.... (I'm in the south remember)
"Education is Paromount" at a High School
"Roaches No charge" at a restaurant that pissed us off.
We did avoid profanity, knowing the consequences of that if we got caught. Still kids will be kids.