> But it only took 3,000 reputation to cast a close vote, and 15 to flag to close a question (prioritizing it for consideration by the first group).

Quick context for anyone who isn't aware, rep there doesn't work like karma here: your question getting upvoted is apparently now +10 (used to be +5), your answer getting upvoted is +10, either getting downvoted is -2 (and costs the downvoter, they get -1), plus a few others.