I think you mean https://en.wikipedia.org/wiki/Motte-and-bailey_fallacy :

    An arguer conflates two positions that share similarities, 
    one modest and easy to defend.. and one much more controversial....
    The arguer advances the controversial position, but when challenged, 
    they insist that they are only advancing the more modest position.

Thank you for pointing out this argument fallacy. I've certainly seen it and been unable to articulate what is going on and why it feels like an argument in bad faith, and now I have a name for it.

Not exactly. Motte and Bailey is a fallacy as an argument, but memes are not arguments. You can think of it as a distributed version of Motte and Bailey: someone out there surely is trying to actually abolish policing, but if you fish the internet for arguments in favor you only get people looking to reform

The answer, like to most of these kinds of issues, is to avoid arguing against internet memes. Have a debate with a singular person on an agreed upon position, or don’t debate at all.