Nope, you can’t
You would have flagged my post not because you wanted the badge but because you wanted to prove a point. If you had (1) never read this topic and thought to yourself that flag badge looks niiiice, I’ll just flag a random post to get it and then did that, that would have proved WildSage’s point. Or, if (2) now you decide you do want that flag and decide to flag a random post to get it. That would also prove their point.
Taking a step back I think we have 2 questions here: (a) I think it is exceedingly unlikely that someone will randomly flag a post just to get the flair and (b) why do I say No, this is not going to happen when I perhaps mean it is exceedingly unlikely that this is going to happen.
To adequately treat both things would require 2 longish essays, so I’m reluctant to go into that.
But, for your amusement, here’s a start on why I think it is exceedingly unlikely someone will flag a post just to get the flair.
In no particular order:
(1) They haven’t yet: this forum is now 3 months old, there are 1890 users but only 16 people have the flag flair, all of them I think conscientious posters who didn’t flag a post just to get the flair. So the current percentage or promillage is at 0%.
(2a): I think the fear of random flaggers is because of a perceived similarity between that and cheating for points. But they are wholly different. Getting as much points as you can is just a (fun) way to mindlessly while away the time that doesn’t (really) impact anyone (if you don’t really think about it). Lots of games take advantage of this. The games aren’t all that fun, but you keep coming back because you want to increase your score. Memrise also capitalizes on this to a degree. The people who decide to cheat for points are just a little more competitive than usual and don’t mind wasting their time to see themselves on the leaderboards. Also it’s a fun little game to try to find out how to cheat the system. That teaches problem-solving. I’m sometimes tempted to do this myself. I don’t because I don’t want to get banned and I’d rather code something useful.
Flagging to get a badge however is not fun. The first thing you have to think is: fuck this guy, I don’t care about him, I just want this badge. No-one who is on this forum long enough to know about the badge thinks like that. And no-one who isn’t is either.
(2b) Cheaters for points can be ignorant of the effects their actions have on Memrise, or can easily ignore it. Random flaggers can’t, because they are an active part of this community (if they weren’t they wouldn’t care about the flag badge or even know it existed).
(3) Just a rephrasing of the former points: it goes against human psychology; people are mostly good and want to perceive themselves as good. There is no way that I can see that you can flag a random post and perceive that action as good, so I don’t see that happening. You have to have a different reason, like this is a bad post or this is a bad person to still perceive yourself as good.
…I might have some more reasons but can’t think of any now.
Someone randomly flagging a post is going to be such an outlier that you don’t need to think about them when you design your system. When the 1 in 10,000 person shows up who does randomly flag a post, staff can deal with that when they come upon it (which is just to ignore the flag).
Some likelier scenarios I think are (1) people who are too enthusiastically flagging posts and repeatedly flagging posts that shouldn’t be flagged. Thinking they are helping when in reality they aren’t really. And (2) an unpopular poster or a poster that writes in a perhaps more confrontational style than the majority here getting their posts flagged more than necessary.