Security guards have a bad reputation for wanton enforcement of arbitrary rules. Is it deserved? Watch this video of a guard at Ground Zero silence a bunch of North Carolina school kids while they’re singing the National Anthem and decide for yourself.

In the video above, posted by a parent of one the kids last week, we see a chorus from Waynesville Middle School, of North Carolina, performing the Star Spangled Banner—with harmony!—only to be shushed and booted by a uniformed security officer (the clip has been viewed over 500,000 times). The New York Times reports that the National September 11 Memorial Museum in Manhattan has apologized for the choral crackdown:

“The guard did not respond appropriately,” Kaylee Skaar, a museum spokeswoman, said. “We are working with our security staff to ensure that this does not happen again with future student performances.”

Apparently, the issue was a $35 permit required for such a performance, which the school group did not acquire. On the one hand, it’s understandable not to want a place of solemn remembrance to become, far down the road, just another large public square in New York filled with drum circles and 9/11 Spider-Men. On the other hand, good rule of thumb is to avoid being caught on video telling little kids they can’t sing the national anthem. On the third, mutant hand, maybe this sort of thing is going to happen forever now that we’ve turned the site of a horrific, world historical terrorist attack into a tourist destination.

Either way, these kids can sing!