Ask HN: Using the Cloud as infrastructure for a security product

Do you think it is reasonable to use the Cloud (eg AWS, Google, Rackspace, etc) as core infrastructure for a security-related product? Would you use a Security as a Service product hosted therein? What would drive your considerations? I'm trying to decide if/how I can leverage these tools in my company, and feedback from this group (technical early-adopters) on how you feel about that, as well as technical implementation considerations, would be hugely valuable!