I don't have mod status here so can't use the extra tools available to moderators, but it looks to me from a quick search that they are being removed, just not quickly.
For instance if you do an an Advanced Search for threads that have 'http' in the title, it finds 5.
2 of these are 'genuine' posts, the other 3 are spam, one from today, one from yesterday, and one from 21st October.
Now not all spam posts have 'http' in the title field, but most of the stuff being posted here recently has, so that's a good indication that they are being removed.
I'm guessing that someone has been given the responsibility of removing them at the start or end of each day he/she is at work, so they might be about for a couple of days if that person is not at work.
As said before, just ignore them.