A spam problem has been discussed many times at HYIPNews. However, it still exist and will exist unless all administrators in HYIP field fight it and investors don't invest in projects that are advertised in such a way. In that case spam will be meaningless. If you read programs' TOSes, you will notice that most of them claim that they can not be advertised through spam. However many irresponsible admins don't do anything when this rule is violated. Fortunately, there aren't too many of them and there are admins who do not tolerate spam.
For example, the admin of Online Investment Bank (onlineinvestmentbank.org) has suspended the account of a user who used spam to get referrals: “We never send any email containing invitation or linking to our web site. The members who send any Spam email containing our web site link will suspended immediately. Today we have suspended user "hyip" from our program for spam !” I suppose, no one will advertise Online Investment Bank through spam from now on. And let the admin of this project be an example for everyone.
If you are thinking about making a deposit in Online Investment Bank, I remind you that it offers only one investment plan: 7% daily for 20 business days with principal included in your daily profit. The minimum deposit amount is $10 and the maximum is unlimited. Your total return at the end of the term will be 140% which is 40% of pure profit. The break even point is 15 days. Compounding is not available. The referral program has 3 levels and offers 1-4%. OnlineInvestmentBank accepts PerfectMoney and LibertyReserve.