I saw them off and on during the past five or six years. I noticed that they flew very late at night, often around 3:00 AM. They resembled jellyfish more than triangles, and their lights were different than those on most craft. They strobed more than flashed, and they blinked in irregular patterns. They resembled the X-47. They weren't identical, though. The sides were rounded and smoothed rather than sharply edged like most triangular craft. They sometimes seemed like they "swam" through the air rather than flew through it.
Umm how about a location for starts.