I know Mt. Gox made it difficult to withdraw your money/coin from the exchange near the end, but they learned a hard lesson not to keep their coins sitting on the exchange (I sympathize, it's something I struggle with too periodically, it's just so easy to keep it sitting there).

The digital currency landscape is still in kind of a 'Here be Dragons' unmapped territory situation. No one knows exactly where it's going to end up, but they know there's riches to be had if you can figure out how to maneuver through it, or get lucky.

I'm pretty obsessed with both bitcoin and several altcoins, and I admit that I'm gambling with them, possibly more than I should, but I don't trust ICOs at all. Almost all of them seem to be money raising (for the company) schemes for what's essentially total vaporware. I'm sure some will manage to hit it big and make people a lot of money, but I fully expect a large percentage of them to crash and burn once the initial novelty and exuberance wears off and a lot of those companies to take that money and vanish, and there doesn't seem to be any decent method to evaluate which ones are the good ones and which ones are the total stinkers.