On /tv/, it's a term used by people who obsess over child actors/models, and post legally-grey-area pics of them. Their posts and threads are eventually deleted, but not very fast, so they still gain a presence in the community. The posters are detested by /tv/ because they're for-real pedos, and they're given no tolerance by the community or moderation.
On /a/, the term is just used by lolicons. While /a/ has been taking a harsher stance toward loli content (e.g. deleting loli threads, or deleting threads about loli-centric series that don't make neutral-sounding OPs), posts about loli-centric series and about lolis in series are still generally allowed on /a/. The only ostracization usually comes from bait posts that try to equate 2D and 3D, and those are usually deleted eventually.