[leot]

CrushMail (or something like it) circulated among my friends at some point during the late 90s. Perhaps she was fibbing, but the one girl who I think I matched with (??) said she had just clicked on everyone.

So, plausible deniability wins.

On a completely different note: this is basically a non-issue after one's mid-20s, by which point most people seem to have the ability to appropriately inquire after those whom they have an interest in, and have a reasonably good sense for who is eligible and who isn't.