This threat seems very, very likely at some point. The cost of an attack wouldn't actually be that much to pull off. Even a short term (i.e. much cheaper) attack could completely destabilize the faith people have in Bitcoin.
Are we just waiting for an attack to occur before actually doing anything?
An attacker that isn't motivated by money will eventually attempt an attack. This isn't an "if", it's a "when".
Some billionaire, inherited wealth rich kid could completely devastate Bitcoin for under $50 Million.
Some people love to wreck shit. Rich guys that love to wreck shit? It could get ugly.
Somebody console me. I want to be wrong. What am I overlooking?
What
can we do about it? That's the nature of Bitcoin, you can't do anything about it, unless the majority agrees on something. And how is the majority being determined? By hashing power, that's the limiting factor and the whole idea behind Bitcoin!
Majority is easy. When hard fork comes, ppl will use version 1 or version 2. Version that has more users wins. No problem about it.
Problem is what exactly CAN be done? When you start digging into the topic, you find out that ppl had ton of ideas, and that every single one of them fails even in theory. This topic is nothing that can be fixed by anything shorter than "revolutionary solution", and we can agree that that kind of solutions don't come from day to day.
Yeah, a fork can be done at any time people can't agree on a specific way to adhere to bitcoin's rules. If for example tainted coins become a topic or some state forces the protocol to incorporate certain things, a hard fork may occur. People will then have to decide which chain to follow. Of course, bitcoins value will suffer greatly. But that's how it works - by definition!