Because fundamentally misunderstanding physics annoys me

I just read an article where some moron is writing that people should build their own anti-satellite system to blind spy satellites using laser pointers.

Thinkgeek sells this laser pointer with a beam divergence of 1.2 milli-radians.  

Ok, fine, this page lists a few others, and it looks like the best they can come up with is a 0.5 mrad.  Geosynchronous orbit is 35786 kilometers up.  Using the power of tan(x) ~ x for small x (and noting that 5e-4 radians is really small), this gives a beam diameter (assuming a point source at the laser) of 17.893 kilometers.  This seems to work out to the irradiance at that satellite is something like a factor of 3.1234e-15 smaller than it is at the source.   In conclusion,

Thank you, Lois.