I hate grave robbers! It’s dishonorable and downright sick.
Is the Titanic really a grave? It’s quite possible there are no bodies within the wreck. Have any been found? Did anyone actually go down with the ship? I would think everyone got off in an effort to survive, and their remains eventually sank at various spots around where the parts of the hull came to rest on the bottom. In some cases that could be miles away.
It’s an accident site. Any remains found could be reinterred with a proper marker, even if the victim remains unkown. Artifacts have been retrieved from ancient battle sites, burial grounds of plague victims, and countless other places of human demise. As long as proper respect is made and dignity observed, I see no issue here.