There aren't any.

The tally at the time of me seeing this is 10 up votes vs 4 down votes with an overall score of +6 (10 - 4 = 6). When content is posted, all sources get a +1 which becomes the default score (+1), so however many times you vote based on different sources, your vote still counts as a single vote using the 'best of' method, meaning that we tally all of your votes based on sources and either give it the effect of +1, -1 or 0 (no effect). As for up votes that aren't from a specific source, this is also not possible, they either have to come from the Front Page, the Local Feed or any of the tribes that the content exists in. It is however important to note, that the vote break down shows TALLY scores and not total vote counts for each source, this means that the Front Page score of 0, could be 2 positive and 2 negative votes. Also negative votes even if done multiple times by the same "voter", are only counted once in the final tally.

Either way, there is a lot of calculations being done behind the scenes with votes, and we figured it would be best to display it so that everyone can see what is happening. The last thing I expected while reading through this thread with my morning coffee in hand was to see such well thought out theories of vote manipulation come to light. I mean, the simple reason is out of the question of course, I guess it's the more boring answer to that very tantalizing question.

The Indians are quite good at this.