[PeterisP]

It is somewhat similar, but substantially different - we can make a solid argument that the likelihood of getting invaded by hostile aliens in the nearest century is far lower than 1%, and also if such an invasion does happen, then building a giant space laser won't make any difference at all.

The key difference between powerful alien invaders and us creating a powerful alien entity that we can't control is that the former either will or won't happen due to external circumstances, but the latter is something we would be doing to ourselves and can avoid if we choose to.

[nradov]

Bullshit. You can't presume to quantify the probability of either event. You're just making things up. All of the arguments are built on a foundation of sand. This stuff falls in the realm of religion and philosophy, not hard science and math.