I'm sure there are many sellers on exchanges like localbitcoins and Paxful still sell Bitcoins without asking for an ID or Phone number verification [For some odd reason I used to have these options within localbitcoin's search feature, but I no longer see them]. The central parties in most countries tend to think of this as money laundering as they can't keep track of who's buying the cryptocurrencies. I feel this seems an appropriate measure, but it no longer allows buyer and sellers to buy Bitcoins anonymously.

Similarly, is it also a crime for a buyer to purchase Bitcoins or other cryptocurrencies in a similar fashion without providing any ID? Isn't it also possible for the authorities to track via the seller's bank accounts the buyer's transaction details and trace back to the buyer, considering that a Bank to Bank transfer has taken place?