My English is not well to understand what does AnonyMint speak about. I just feel, he sheds light on possible fundamental vulnerability that says unlinkability is not compatible with longest chain rule of proof-of-work. I may mistake.
Key images are a unique property of the CryptoNote protocol that prevent double spends.
To quote gmaxwell and andytoshi, one of which is a core Bitcoin developer and the other is someone who truly understands both mathematics and cryptography:
That is the end of this discussion, and I would suggest we not get caught up in random and nonsensical panic attacks just because someone claims a particular flaw exists when it doesn't.
Thank you very much for answer, fluffypony;
smooth, could you add this to FAQ too, as you are likely a thread owner?