Crux of the issue is using multiple accounts to claim giveaways. I see it a lot, never really cared before, not sure why I'd start now.

It isn't fair to hold one user to a higher standard than other users and single them out just because they also volunteer their time to help moderate the forum (if it's true). Though it is something I would keep in mind about a person if I saw it.

It seems more like a violation of a site's TOS, than a scam, and not really deserving of negative trust. If that deserves negative trust, then so do people who abuse dropbox referrals, or buy Facebook/youtube likes and views, pay people for using their referral links, buy and use .edu mails to get discounts on whatever, etc. All these actions harm the company or other users in some way.