Whenever I read a news story about some fantastic and unexpected discovery made by an astronomer somewhere I wonder if it could be artificial, ie the result of extraterrestrial activity.

For example I've read about gas giant planets discovered orbiting their stars closer than planet mercury when models of planetary formation predict that this is very unlikely. I know that solar energy is extremely plentiful at this distance - could extraterrestrials of unimaginable evolution have created some artificial planet for this reason?

Gamma ray bursts haven't really been explained yet. Pulsars, quasars, things that seem to be unique in the universe... But why would extraterrestrials create such things? Here's one possibility that no one has spoken of:

Programmable Black Hole Computers

A 1-kilogram black hole computer could theoretically perform 10^51 calculations per second. Suppose some godlike race created the black hole at the center of the galaxy just for this reason? How powerful would that computer be? Even if they were curious about emerging civilizations such as humans, what would be the point in opening a dialog with us ?!?!