Are sleeve bearing type case fans okay for mounting laying down(horizontally)?

[DarkDubzs]

So while ive been looking for some good case fans for my rig, i eventually almost decided on getting the Cooler Master 120mm Silent Case Fan 4-in-1 Value Pack, but i think its bad to mount fans like that up or down. The reason being because the sleeve bearing type it has are not good for mounting horizontally (laying down). Im not sure if this is true, so im asking here. Also, according to THIS, the fan might actually spin up out of its place if mounted on top blowing out as an exhaust fan. That would be a problem for me because I plan on mounting a couple on the top vents of my NZXT Source 210 case as exhaust fans.

So, is this info accurate? Please leave any answers or feedback. Thanks!

 

[dottorrent]

This will help you -

http://www.gamersnexus.net/guides/779-computer-case-fan-bearing-differences