The loss that circumvented websites may suffer extends beyond the collection of demographic data.
If a website uses, for example, Google Adwords, the relevant site may see a reduction in revenue from that income stream because illegitimate users click through say, only two screens, instead of say, five.
A website such as mine – Legal Tender – would also suffer loss. Legal Tender is a lawyer – client matching service. It is free for consumers, but lawyers pay a flat fee if they win a tender. If clients are bypassing the registration process, they won’t be able to post cases. If clients don’t post cases, law firms don’t pay referral fees, and we suffer loss from that revenue stream as well. Further, I think the company needs to look into whether it could be aiding and abetting (1) the original user who provided the login details and/or (2) clients of BugMeNot.com who use fake login details – to breach the websites’ terms and conditions.
(This is not to be taken as legal advice as I am no longer a practicing solicitor).