I bumped into this question in the ZenCash thread. This issue is not unique to Bitcoin. It affects all blockchains.

My answer is that this issue isn't unique to cryptocurrencies. Steganography can be applied to many forms of data storage and communication. Be it stock market prices, radio waves, favicons and web ads... I'm sure it's possible to encode illegal data with sesame seeds on hamburgers.

If this issue is being used to bring down cryptocurrency, it opens a Pandora's Box for every possible carrier and unwilling recipient of steganography.