You can invest in whatever you want :-).
It's the startups that will get in hot water if they take your money, since you're not accredited investors, http://www.sec.gov/answers/accred.htm
a charitable organization, corporation, or partnership with assets exceeding $5 million;
a director, executive officer, or general partner of the company selling the securities;
a business in which all the equity owners are accredited investors;
a natural person who has individual net worth, or joint net worth with the person’s spouse, that exceeds $1 million at the time of the purchase, excluding the value of the primary residence of such person;
a natural person with income exceeding $200,000 in each of the two most recent years or joint income with a spouse exceeding $300,000 for those years and a reasonable expectation of the same income level in the current year; or