I wanted to put on an Amazing Grace hat that I earned on one of the sites and zooming in I saw that the grey symbol on it resembles the Reichsadler, the coat of arms of Nazi Germany. I admit that for people not living in Germany this maybe not so obvious or even completely unnoticeable and insignificant but for people in Germany - who are very sensible to this topic - it's a striking similarity. I put them together so that the resemblence is more evident.
Keeping in mind this topic about communist symbol I think SE should be more careful in choosing what they put on the hats.
PS. I know from the answers now that it’s (loosely) based on US Navy symbol (still looks more like Reichsadler than any other eagle on any other coat of arms). Which doesn’t make things better - why do we have military symbols on our hats in first place?