An interesting feature of people voting from abroad is that it is very easy to make it very easy or very hard for them to vote, and the choice between those two options tends to depend on how the current government thinks those people are likely to vote. So some countries allow expatriates to vote, but voters have to fill in a load of forms and then turn up with various document at the embassy at a particular time, while other countries proactively hunt down their expatriates and send them a form in the post with a prepaid envelope.