I actually disagree, because they're a deterrant. "They show up after it happens" is an argument that could be applied to any deterrant, so it's obviously a bad argument. Police are a problem for other reasons than that they literally don't prevent any crime.
They're not a very good one considering how they have a very poor case closure rate for serious violent crimes, and the state and federal justice systems of the US are disturbingly okay with false convictions and excessive retribution.
c/politicalmemes has a quality standard for memes? Besides which the argument was they might still be useful, and the versions we've seen in the US so far have shown to cost way more than their value (and that's before we get to asset forfeiture).
At this chapter it's long time to start implementing programs with the goal of completely replacing law enforcement in the US with other systems, including enough benefits to assure people aren't driven to crime by desperation.
Postponed, supressed or relocated potentially but not prevented and when crimes are postponed or supressed as such the desperation increases resulting in more violent and destructive crimes.
The only way to prevent crime is to deal with the conditions that cause it.
It is both true that police show up after it happens and they don't prevent crime? No -- there exist crimes that are prevented by the police. I'm sorry but even if this meme is batting for my team it's in my best interest to shoot it down because it just makes us all look stupid. I agree with the conclusion this meme makes, but the first half is so obviously wrong it is worth negative points in my opinion.