Data Embedded in Transaction with Unknown Protocol (what's this?)
2 Outputs Created
0.00000001 BTC Null Data Transaction
Estimated Value Sent : 0.00000001 BTC (more)
"Estimated Value Sent" excludes known change addresses. For example, let's say we have a single transaction where address A sends 1 BTC to address B and also 1 BTC back to address A as change, then only 1 BTC is estimated to have been sent. Proper use of a new change address for each transaction (like all HD wallet implementations) obfuscate this feature.
You can also embed data into the Bitcoin blockchain.