[6510]

Could do that before the user is forwarded to the website. Remove them for a day, then 2, then 4, then 8, 16, 32, 64, 128 etc it is not expensive to keep checking. Could send email too.

You'd probably want to measure click though rate and do manual review. Could also have a redirecting page so that the back button allows the visitor to flag or report something.

[ShadowBanThis01]

But definitely only remove them for powers of two days, because... geek cred.

[6510]

I use it for rss feeds, it really follows how likely it is for a feed to return. Checking every day was slowing things down.