So it's a bit cargocultish, really. But the source, as I understand it, is that actual lawyers who are not your lawyer, has to make it clear that they're not giving you legal advice for liability reasons. If a lawyer who is actually your lawyer gives you bad advise and you lose out because of it, you can sue him (and his insurance). But the insurance only covers actual clients, not strangers on the internet.
It's a little funny how this applies to legal advice, and not, say, medical advise. People on HN will happily report on experiments with Ritalin, mushrooms and sleeping patterns, they will encourage you to quit your job and do a start-up - but "You should write a courteous, factual reply and talk to a lawyer" has to come with a long disclaimer :)
It's a little funny how this applies to legal advice, and not, say, medical advise. People on HN will happily report on experiments with Ritalin, mushrooms and sleeping patterns, they will encourage you to quit your job and do a start-up - but "You should write a courteous, factual reply and talk to a lawyer" has to come with a long disclaimer :)