some u.s. citizens living abroad are encountering problems while trying to register to vote on line:

Customers of internet service providers (ISPs) in at least 25 countries — including Wanadoo in France and Telefonica in Spain — have been denied access to the site of the Federal Voting Assistance Program (www.fvap.gov), the International Herald Tribune reported.

internet security is one thing but blocking some of the largest isps doesn't seem to be the best solution to this sort of problem. it appears that the problem has been resolved, but explanations surrounding this case are a still rather vague.