Has any illegal data been saved in the Block Chain?
While working on my master thesis I used the AACS encryption key (09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0), considered an illegal number, as a basis for creating a fake Bitcoin address - 1ujTAfEQh2obwdt72GrmXonakx2RxvYpX. A 1 Satoshi transaction was sent to that address from address 17TQLZvXjKTrUyRnV9DuQs4RVDgNjUPeXQ. The transaction was encoded in block 177653.