Apple once sold a monitor that would sometimes have a line at the bottoms of the display. Apple support said to strike it firmly with the hand on the left side of the monitor.
Long time ago, early terrorist period, a person was told to open a MacBook and boot it to certify it wasn’t an explosive. When he booted it, it crashed and showed the figure of a bomb with a lit fuse. The guy reflexively said “Oh, a bomb.” That didn’t go well with the TSA, but it was finally resolved.
I’ve got one. And a matching Grape iMac to go with it.