I think a list of btc scam sites should be made from which people should make a note of those sites and stay alert.
That's not going to help either. There are so many scam sites made everyday and check it every single of them. The most effective way to avoid being scammed is also to avoid Hyips, doublers and all investing sites because they all end up scamming people no matter how long or short they site runs.
Yes, many lists of scam sites were made, but they are worthless now... Scam sites appear and disappear really fast, they shut down and come back with a new name, on the internet it's very easy to do this kind of thing. There are many new sites that aren't on lists that are scam too and someone only looking through lists will be scammed anyway... Always doubt about sites legitimacy and ask people their feedbacks about it.
(And I think this thread should be at Scam Accusations section, no?)