It's not a service, its a personal bot that you run on your personal account. Try it out and check out how it works on hiveblocks. Basically for the most part your account IS the whitelist.
One possibility of abuse might lie in the plausibility of ambiguity of the created comment.
If my vote is worth $0.10 and your vote is worth $10, and I use this bot to up-vote an old post by you through a comment like this, you could up-vote the same comment that I up-voted with $0.10 with your full $10 vote, basically doing a huge self vote.
If the comment made is ambiguous in that sense (it probably is right now, and I think your alternative wording is too), your "I didn't know I was massively self up-voting" will be plausible.
I think the wording of the comment needs work. I don't want to make it a data dump, but it needs to be unambiguous that an up-vote by the main beneficiary equates a self-up-vote and might be viewed as abuse.
O, I see. In that case... I totally misunderstood the assignment and would need to re-assess the potential scenarios. Figuring out how to be running your own script can already be a pain in the ass for most people.
Which can be a gift for tech-savvy bad actors, right?
Can you imagine gifting this to a known scammer who has the same or a higher level of understanding of tech? Given the fact that they could make it themselves, let's say they didn't due to time management or whatever reason. How would you secure it before handing it out? What things would you think of?