I think paranoia over information already part of public record is something to laugh about, yes. Let me know when they start collecting SSNs and bank account numbers.
Actually... this could be a serious problem, legally speaking, especially if enough people started to make a stink about it. I'm assuming that given Fanime takes place in California, the organization is also registered as a non-profit in California, and that California law applies.
Particularly:Information-Sharing Disclosure, "Shine the Light" - California Civil Code sections 1798.83-1798.84. This law lets consumers learn how their personal information is shared by companies for marketing purposes and encourages businesses to let their customers opt-out of such information sharing. In response to a customer request, a business must provide either: 1) a list of the categories of personal information disclosed to other companies for their marketing purposes during the preceding calendar year, with the names and addresses of those companies, OR 2) a privacy statement giving the customer a cost-free opportunity to opt-out of such information sharing. Financial services companies subject to the California Financial Information Privacy Act are exempted from this law. See the Recommended Practices, pdf in relation to this law.
And:
Online Privacy Protection Act of 2003 - Online Privacy Protection Act of 2003 - California Business and Professions Code sections 22575-22579. This law requires operators of commercial web sites or online services that collect personal information on California consumers through a web site to conspicuously post a privacy policy on the site and to comply with its policy. The privacy policy must, among other things, identify the categories of personally identifiable information collected about site visitors and the categories of third parties with whom the operator may share the information. The privacy policy must also provide information on the operator’s online tracking practices. An operator is in violation for failure to post a policy within 30 days of being notified of noncompliance, or if the operator either knowingly and willfully or negligently and materially fails to comply with the provisions of its policy. This law takes effect July 1, 2004.
I just went digging around the Fanime website, and couldn't find any stated privacy policy. (Granted, I'm pretty braindead from the long drive home today and may well have missed it.) In any case, I'm pretty sure that the former would apply to data collected during at-con registration, even if the answer is "We don't share it with marketing third-parties and only retain such information to contact you and send you updates." Pretty sure the latter applies to online pre-reg, in much the same way.
Standard disclaimer: I am not a legal professional, just somebody vaguely familiar with hunting up bits on laws via Google.