I for one would like to know what the heck this sign is about. The phrase “radio frequency emissions” is pretty tantalizing on its own. The preceding “all” is next level — like, versus what? Is there a different sign that stipulates a subset of signals? And what made this situation an “emergency”? Was something being disrupted? How were the offending emissions first noticed, identified, and triangulated? I would really like to know. (Also, my phone took this photo from about 25 feet away through a windshield, and the sign is barely the size of an 8 1/2” x 11” piece of paper, and this is only the top third of the sign. Kind of amazing.)
And I got an informative response via Threads.