Jonah: Yes, arrests are a part of the overall “broken windows” strategy, but I’ve always understood property maintenance to be at the heart of the matter. I’ll defer, of course, to Wikipedia’s entry on the Wilson-Kelling concept:

The book is based on an article titled Broken Windows by James Q. Wilson and George L. Kelling, which appeared in the March 1982 edition of The Atlantic Monthly.[1] The title comes from the following example:
“Consider a building with a few broken windows. If the windows are not repaired, the tendency is for vandals to break a few more windows. Eventually, they may even break into the building, and if it’s unoccupied, perhaps become squatters or light fires inside.Or consider a sidewalk. Some litter accumulates. Soon, more litter accumulates. Eventually, people even start leaving bags of trash from take-out restaurants there or breaking into cars.”A successful strategy for preventing vandalism, say the book’s authors, is to fix the problems when they are small. Repair the broken windows within a short time, say, a day or a week, and the tendency is that vandals are much less likely to break more windows or do further damage. Clean up the sidewalk every day, and the tendency is for litter not to accumulate (or for the rate of littering to be much less). Problems do not escalate and thus respectable residents do not flee a neighborhood.
The theory thus makes two major claims: that further petty crime and low-level anti-social behavior will be deterred, and that major crime will, as a result, be prevented. Criticism of the theory has tended to focus only on the latter claim.

You can’t arrest Wikipedia vandals, though Wikipedians are able (I believe) to contain the mischief by constantly fixing it. Seems like “broken windows” is a reasonably good parallel to describe what they’re doing and why it works (at least in theory).