According to this Science@NASA article, the MESSENGER probe will fly past the planet Venus today on its way to Mercury. As part of the flyby, MESSENGER will fire a laser at Venus. When MESSENGER reaches Mercury in 2011, it will shoot its laser at that planet too.
Is this really a good idea? How are the inhabitants of these planets going to react to unprovoked laser attacks by a probe from Earth? I hope this doesn’t set off an interplanetary war. At least we’re not attacking Mars yet — although the Martians are probably rather annoyed at us anyway, because of . . . well, just watch this video and you’ll understand why.