There are many negative comments abount participating in ICOs nowadays because it might be scam or it may not succeed. If you are planning to join in any ico, have a research first regarding the ICO you're planning to join. See their project if it has a potential to succeed or not.
I hope most of the people follow this advice. meanwhile, some ICOs and their teams seemed to us so good...and they vanished. yes, it is also a great risk to make these investments, but the riskiest guys now are rich.