I guess fraudulent is not preventable but you can minimize being a victim if you will be very vigilant in your actions towards your investments. Doing more research before engaging to something which includes money will reduce the chances of being a victim of fraudulence.
Yes, we really should search Google for ways to avoid investing in these types of scam projects. There are lots of bloggers at google who make quality posts on analyzing ICO projects at hot times (2017) and it's really helpful. I have read it over and over 100 times to help me be more careful in investing. You can search in the link below, it will be more complete.
https://cointelegraph.com/ico-101/how-to-choose-an-ico-to-invest-in