If the tool shows slightly a bit over 50% not powered up, the account requires manual check though - it might mean that the user recently received the reward. I think it's the most effective while checking long-term transactions, like for a whole month.

Agreed. Additionally, the tool does not consider any giveaways that many might be doing. While it is easy for me to filter out the funds going out to exchanges, it is impossible for me to know if the user has a genuine giveaway. Many might try and game the system by creating alternate accounts and that would not help the genuine people who are actually powering up.

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