I've just completed my on-line application form a US visa (what a process that is!)

I noticed in passing that Libya, Somalia and Yemen are now 'on the list'
So if you've been to any of those countries since March 1, 2011 then expect to have your ESTA cancelled.
Interestingly - "At this time, the restriction on Visa Waiver Program travel will not apply to dual nationals of these three countries." Unlike dual nationals of Iran, Iraq, Libya and Sudan.
Government announcement here - https://www.dhs.gov/news/2016/02/18/...waiver-program