Only the most highly-educated Bitcoiners are able to think of realistic risks to Bitcoin – people who have spent hundreds, or thousands, of hours on the subject.
Every armchair critic comes up with the same old criticisms which have already been debunked, but because they have a superficial understanding of Bitcoin, they think their criticisms are valid, and they may not even understand the rebuttal – it takes a bit of effort.
Those that put in that effort see how weak these armchair criticisms are. Then, with more knowledge, they come up with better criticisms – but people who are further along the path of understanding than them, have already dismissed these critiques too.
As understanding improves, potential weaknesses of Bitcoin become more sophisticated, and the rebuttals harder to think of (but they are there). After three years of searching for weaknesses in Bitcoin, I have come up with many and moved past all of them to my satisfaction – so far.
Here, I will accumulate links to Bitcoin FUD that I debunk.