It now returns a blank page, so you'll see empty space where the map should be rendered. No errors should be shown to your web site visitors.
The map fails to load for some site visitors, giving an error about Google Maps API being disabled for the site. The error message does not seem accurate, since aprs.fi is nowhere near its usage limits, and an immediate reload of the page typically loads just fine. The error is sporadic, happens to some users all around the world, but not everyone (I haven't seen it), on all browsers (IE, Firefox, iPad, etc). The issue is being discussed on the aprs.fi discussion group.