(please don't mind the poorer then normal spelling i am posting from a work computer)
sorry but it'a mostly a myth that the internet is that reseliant.
the hosting company that hosts this place and the other peak oil sites do not 'just' host these sites. They like many others host hundreds to thousands of other sites as well. such a ddos(disatributed denial of service) attack might make them tell the people who manage this site that they will no longer accept their busnius or demand that they pay a much higher rate. because this is only one site out of many they host and it's preventing them from getting revenue from the other's.

The effect of blacking out the internet sites might not be intended when they start to tell the populace of peak oil happening now or in a couple of years on the msm. but as you said though they will take advantage of it.

Best to brush up on shortwave radio.