Sorry, but I don't have time to read the previous posts. I just wanted to say, that if we create a black hole, it wont really be harmful if it's contained, and it has no possibility of growing in size unless it consumes massive amounts of matter. Even if somehow it dropped to the ground... it shouldn't do too much, as it would be so small, as would its gravitational well. Although, I guess if for some reason it was getting massive amounts of raw energy from something, it could grow in size due to E=mc2 (equivilent exchange of matter and energy). Are black holes spherical? I mean, they should be, shouldn't they?