For all of the grief Bitcoin gets, here's something entertaining: Someone transferred bitcoins worth close to $1 billion USD on Tuesday morning, a move that was public for everyone to see while the identities of the sender and receiver remain unknown.
Big money moves hiding in plain sight tend to be events of some interest among Bitcoiners. Decrypt noted that the sending wallet was recognized as the largest Bitcoin wallet not known to be associated with a business such as an exchange. This means that it could belong to a wealthy private individual, or it could really belong to an exchange, investor, or other business that is simply currently unknown. There's no obligation to publicize which Bitcoin addresses one controls, and if nobody else puts two and two together, one's activities may remain shrouded in pseudonymity.
If the Bitcoin wallet belongs to someone legit, then it's likely the transfer was internal to the business, or it represents a large purchase of goods or services, or the sale of bitcoins. Regardless of what it was, the business would be expected to pay taxes in any relevant circumstances.
If the transfer wasn't legit, well, pseudonymity and the ability to freely move money without the pre-approval of an authority is the point of Bitcoin. That being said, law enforcement is certainly aware of Bitcoin at this stage in the game and if I'm talking about this transfer then I'm sure more important people could be, too.
The public nature of Bitcoin's blockchain, and other cryptocurrencies like it, means that pseudonymous transaction information is publicly posted in a record of transactions stretching back to when the system was switched on. Besides the Bitcoin mystery at hand, a transfer of roughly $1 billion last year also became an item of interest. And just weeks ago, cryptocurrency-watchers were scratching their heads over a small Ethereum transaction that attached millions of dollars in fees.