I don't know about legal issue, but I had an SK/CO trip OSL-SAN with Ebookers and got a message that my return flight was changed from around 10-11am. to 0600am (Z ticket). They were not able to get me on a later flight and I was able to cancel the whole trip without any fees. Ended up with BA and I'm noe in the Admirals Club in SAN for the trip home and time is 0645pm. A much nicer time to from US to Europe. IMO, everything before 0900am is a nightflight, considering time to spent on security and so on.