They will most certainly do. But they're not the only problem, I'm sure others are scraping the forum too, for whatever reasons. Some users may user archive.is (and its brothers), search engines also do their scraping, the internat archive may do so too (less often though), ... the thing is that if you do such a mistake you cannot ever be sure it was not recorded somewhere (else), no matter the nice guys from the forum delete that from their data.