GURE was always a high risk stock, just look at its short interest for gods sake. Many people liked it, traded it, but they are certainly not a 'cream of the crop' in terms of safety (Especially after numerous short attacks).
CNTF is not a likely fraud as far as I know -- I don't think many people are betting in that direction either. I don't own it because I dislike the industries it operates in and dislike their non-usage of cash + lack of shareholder friendliness.
You want to reduce your fraud risk? Start by investing in companies with less than 5-10% of the float being short. That by itself will give you better results than 'rolling dice'.