This happened to a lot of people recently, it can be used to track which addresses are associated with another. For example, if you send money from your wallet and it includes that satoshi in a transaction, the person that sent the satoshi knows that you also own the other sending address. A way to stop this is to send your coins through a mixer.
I am just interested: can you explain how is this possible or provide a link where is it explained please?
Sounds like BS. It was just spam. How could sending money to an address make it traceable?
Some people in another thread were making out like it was something more sinister. I was worried for a moment.
'Enjoy' is still there though. 
