Maybe on a question show who up voted and down voted this or that so you can tell if these persons are up voting a certain person basically giving away the fact that that person is using other accounts to up vote. Remember the four down vote=hidden question rule? also a good thing to have to check who down voted it.
Doing this can present a lot of problems though:
Lots of voting happens, so by showing it, it'll take up a lot of space on the recent activity, blocking out comments and answers made.
If we see who votes down who, that will only create more tension now that people can see who did it. There will be lots of fighting as to why they did it when they know exactly who voted down.
This whole point issue isn't too big a problem. Tons of sites that use a point system and have the same issues. The points have little to no issue on this site. We all know a good answer when we see one.
To put it short, points don't matter. Even if people are using them for duplicate accounts, it won't gain them a lot of points if their answers aren't that good. In most cases, it actually works against them since most people will vote it down and negate the upvote they got.
