Yea, the government might be able to trace who owns what coins... but how can we... how can we as regular people avoid buying some centralized piece of crap coin, with absolute certainty.
Only way to do it is to do your research.
One of hte worst cryptocoin scams that i have personally ever experienced was the paycoin scam, the developers offered to put a $20 price floor on the coin but when the entire project turned out to be a scam, the whole thing went crashing down below $20(well below).
There was even a joke coin made by some random guy called paycon, that was worth more than the actual "paycoin".
Also, bitconnect is one of these centralized ponzis that have nothing to do with cryptocurrencies. As i said - do your own research and it's easy to avoid them.