Microsoft has an MSDN article that touts the fact that SOAP circumvents firewalls by repurposing port 80 and using HTTP as its transport protocol, even though this is one of its biggest problems. Port 80 is open in most firewalls because HTTP is generally considered to be safe. I imagine that if SOAP continues on its present course, firewalls will start doing more fine grained filtering on port 80, or security administrators will just shut off Web access to their sites. If they choose the latter option, it won’t be good for anyone.