For example, a meme that is harmful to your collective, should be countered or thwarted.
You have at least two options. First is discredit. This works best when the original meme is attributed to a named individual with a reputation they wish to preserve. The revised meme may be even more popular than the original, and therefore the original author is discredited and discouraged from further memeing, to avoid reputational damage.
Secondly, you may try to inform the viewer with counter memes and facts. This is difficult, it may be as difficult as trying to change that person’s worldview.
Silencing a meme only makes it spread faster. I suggest subverting enemy memes, much like what /pol/ does with shills.
Some people seem overly forced. Just look at the “#Metoo” movement. They tried to force, it didn’t go anywhere because it wasn’t organic, and they don’t possess the will to power a meme