On Tue, 30 Dec 2003, Bill Stewart wrote: > The reason it's partly a cryptographic problem is forgeries. > Once everybody starts whitelisting, spammers are going to > start forging headers to pretend to come from big mailing lists > and popular machines and authors, so now you'll not only > need to whitelist Dave Farber or Declan McCullough if you read their lists, > or Bob Hettinga if you're Tim (:-), you'll need to verify the > signature so that you can discard the forgeries that > pretend to be from them. > > You'll also see spammers increasingly _joining_ large mailing lists, > so that they can get around members-only features.
This has already happened: Krazy Kevin pulled this stunt 5 years ago on at least one list I was on, joining the list to harvest the most common posters, then spamming using them as sender envelopes after he'd been kicked off. > At least one large mailing list farm on which I've joined a list > used a Turing-test GIF to make automated list joining difficult, ...discrimination against blind users - this is legally actionable in several countries. There is a blind group in the UK taking action against a number of companies for this and the Australian Olympic committee ended up being fined several million AU$ for the same offence in 1999. > and Yahoo limits the number of Yahoogroups you can join in a day, > but that's the kind of job which you hire groups of Indians > or other English-speaking third-world-wagers to do for you. To underscore that point, I've _watched_ cybercafes full of SE asians(*) doing exactly this kind of thing for the princely sum of US$5/day - twice the average wage of the area, even after the cafe fees were deducted. (*) Philippines and east Malaysia. AB