The problem is that in this case, "putting a red flag on [a website]" means creating 10s or 100s of thousands of spam blog comments on random websites. Abusing

The problem is that in this case, "putting a red flag on [a website]" means creating 10s or 100s of thousands of spam blog comments on random websites. Abusing your metaphor further: it would be more like spray painting the phone number of the shady business on every house in town. Certainly the officials would have to notice them then, thanks to your good works! Too bad for the home owners though...