This notable story in the Miami Herald leads with this:
Over just a few days last July, at least two groups of schemers used computers traced to Miami, India and the United Kingdom to fraudulently request the ballots of 2,046 Miami-Dade voters.
So what's the problem? Is the problem the fact that it's online? Portions of the article suggest so (e.g., "This is the e-boletera era of Miami politics.").
But I think the more salient issue is noted later in the piece:
Campaigns highly prize absentee ballots and target their voters. It’s a good way to bank votes early in a state where the mail-in voting period starts weeks before Election Day.
But because absentee ballots are cast out of the eye of election officials, the mail-in style of voting is the most fraud-prone — and the most likely to be at the center of electoral whodunits.
This is the biggest problem when we discuss "voter fraud." It's less the fact that one may request the absentee ballots online; it's the entire absentee balloting system itself.
It's worth considering that most of the debate over voter fraud focuses on voter identification laws, which, in turn, are designed to deter in-person voter fraud--which is, by all accounts, fairly rare (even if difficult to detect).
But while Republican politicians tend to support laws to combat voter fraud, they are less inclined to clamp down on absentee ballots. That's because it puts a number of constituencies at risk for them, constituencies who rely heavily on absentee ballots (namely, military personnel and the elderly).
Florida is ferreting out overseas absentee ballot requests as best it can by checking Internet Protocol addresses, but it's only a matter of time before more sophisticated requests will spoof IPs. Instead, it'll take a more comprehensive look at absentee balloting, and the online aspect is only a small piece of it.