I voted for "something else". I support a random draw or contest of some kind where the entrants are (or represent) hackerspaces/makerspaces. I believe this will result in the scope getting more use, and Keysight and EEVblog getting more exposure among the space's members as a bonus. Theft (and damage) shouldn't have to be an issue; the group will know it's valuable and take appropriate measures to keep it secure.
Now, everyone knows hackerspaces already have oscilloscopes. But they're often old ones, which work but don't do everything the members want. And some spaces are expanding and increasing in quality, but don't yet have oscilloscopes and other equipment to match. (Full disclosure: I am a member of Protospace in Calgary, which fits those criteria.)
If the draw is to be among forum members, I second wraper's suggestion of ~10 post threshold, without those posts all being within a few days after the contest was announced. (I may be a bit biased on this too, because my post count is currently below the 100 that others have suggested. But I think the suggestions of 100 were not well thought out in other ways, which wraper's solves.)
I also think the idea of entrants having to pass a quiz on content from older videos is a good one. However, while I've been subscribed for ages, I haven't watched even half of the videos because a lot of them just don't interest me, so I might fail that.