From the search engine watch

<quote>
Basically, if a company's securities make up more than 40 percent of their assets, then they can be classified as mutual fund company. Google's plea to the SEC was "that it is not in the business of investing, reinvesting, or trading in securities."
</quote>

Googles argument makes sense to me. I'm not sure what the ramifactions are for falling under mutual funds rules, but I'm sure that will be looked at further by a bunch of lawyers

Link:
http://blog.searchenginewatch.com/blog/060825-100100