However, UFFire does not uncontrollably exponentially reproduce or improve its functioning. Certainly a conflagration on a planet covered entirely by dry forest would be an unmitigatable problem rather quickly.
Do you realize this is a totally hypothetical scenario?
http://fusion.net/story/54583/the-case-against-killer-robots-from-a-guy-actually-building-ai/
(An earlier version of this article was titled 'Andrew Ng disses UFAI concerns" which is the phrasing many of the commenters are responding to).