just wanted to report this, probably gets deleted here immediately, but is there a way to keep such "questions" spam out of rss feed too, maybe delay time, till questions is added to front page and rss feed. Ironically, this is the first time I see spam in a SE feed/site, wondering how such a popular site managed it to delete all spam so fast, but felt remembered on old usenet days visiting my SE feed today :)
If you delayed the appearance of posts, then how could the community review them and take the appropriate action? If nobody sees it, then nobody flags as spam or offensive, and it'll eventually appear anyway, only to then be flagged.
Almost all users who saw the question you call "sex spam" (which it wasn't, but that doesn't make it any better) flagged it as offensive, so it was deleted automatically pretty quickly.
The reason that you rarely see something like this on the Stack Exchange sites – despite it being posted; it turns out there are quite a few idiots on the internet – is that the community has the tools to take care of these posts pretty quickly, without having to rely on a moderator being available immediately. The larger the site is (and thus the more crap it attracts), the more people there are that see the post and flag it as offensive, and thus the quicker it gets killed.
On Stack Overflow (which is orders of magnitude larger), a post like the one in question here has a pretty good chance of being deleted in under 60 seconds.
It should be noted that our automatic protection against spam bots works pretty well; the problem is actual humans littering on the site, and for those, technical solutions obviously only work so far.
On websites that allow user-generated content, we have to live with the fact that stupid people exist; all we can do is make sure the community is able to react quickly. Hiding new posts would be counterproductive to that, in addition to also punishing the vast majority of new posts that are legitimate.