"extraction would have to be done without contributing to the instability of the seafloor"
They were looking at extraction couple of years back off the coast of NC.
There seemed to a a risk of destabilising the continental shelf. Will be interesting to see if, in the future, extraction is done off the coast of another country "which doesn't matter quite as much as NC"
edit to include another link :
USGS investigations indicate that gas hydrates may cause landslides on the continental slope.
Seafloor slopes of 5 degrees and less should be stable on the Atlantic continental margin, yet many landslide scars are present. The depth of the top of these scars is near the top of the hydrate zone, and seismic profiles indicate less hydrate in the sediment beneath slide scars. Evidence available suggests a link between hydrate instability and occurrence of landslides on the continental margin. A likely mechanism for initiation of landsliding involves a breakdown of hydrates at the base of the hydrate layer. The effect would be a change from a semi-cemented zone to one that is gas-charged and has little strength, thus facilitating sliding. The cause of the breakdown might be a reduction in pressure on the hydrates due to a sea-level drop, such as occurred during glacial periods when ocean water became isolated on land in great ice sheets.
http://marine.usgs.gov/fact-sheets/gas-hydrates/title.html