More importantly, seeing a meme, knowing where it originated, and recreating it to submit it on another site is the complete opposite of douche baggery. It is literally what you are supposed to do with memes. It's what memes are and what they're for. Also, it's the most noble and helpful thing you can do for the user who posted it. Because if it's a funny meme, you're helping more people enjoy it (which is what they wanted), and if it's a political message, you're helping that message spread (which is what they wanted).
The only time it wouldn't be seen as helpful by the user is if the main reason they posted it is to get "credit" for it - in which case, they're just a dick, and they have no business submitting memes on the internet in the first place (and then you should repost their stuff, just to annoy them).
When I see reposts of things I've made, it almost makes me weep with gratitude. It's the best feeling. It's not quite enough to make up for all the pointless arguments we users have about what a meme is, and when it's okay to repost, but it helps me forget those arguments temporarily.