Azureus open ports - security problem?

[Laurence Vanek <lvanek@xxxxxxxxxxx>]

Have in the past used (with FC4) Bittorrent with my firewall which tests 
as "stealth" when tested with shieldsup on https://www.grc.com. I did 
not need to do anything special with regard to opening up my firewall to 
expose a certain port.  Perhaps Bittorrent has a way around this.

Azureus is a different matter.  Apparently I need to open the firewall 
to expose certain ports for it to work.  Otherwise, I get the infamous 
"NAT problem" when configuring it.  If that is the case,  isnt this a 
security problem with port(s) open when Azureus is not in use.  Surely 
not many are going go thru an open & close port cycle after every use of 
Azureus.