Dont mourn at the dead vs Dont mourn on the dead

Some examples from the web:

• Supports the decision of President Boris Tadic to go to mourn at the Potocari memorial on the tenth anniversary of the Srebrenica massacre;
• The dead are the cornerstone of every homicide investigation.
• They thought she could speak to the dead.
• Luisa believed that the dead kept being present.
• The dead can return given sufficient motivation.
• Unless you can raise the dead...
• In Florence painters dissect the dead.
• People always remember the dead fondly.
• Romero never explained why the dead rise.
• People always remember the dead fondly.
• No, the dead are walking.
• You reported an epidemic which affects the dead.
• Sobbing and moaning to wake the dead.
• - The dead woman we found.
• Youza-youza incense to conjure up the dead...
• Perhaps the dead of their injuries.
• Between the dead ref and the dead judge.
• The dead can't harm the dead.
• This programme is not only an affront to the memory of the dead but, even worse, reduces the dead - and human existence in general - to a marketable commodity.
• Because when you think of the dead the dead can hear you.

Some examples from the web:

• The dead are the cornerstone of every homicide investigation.
• They thought she could speak to the dead.
• Luisa believed that the dead kept being present.
• The dead can return given sufficient motivation.
• Unless you can raise the dead...
• In Florence painters dissect the dead.
• People always remember the dead fondly.
• Romero never explained why the dead rise.
• People always remember the dead fondly.
• No, the dead are walking.
• You reported an epidemic which affects the dead.
• Sobbing and moaning to wake the dead.
• - The dead woman we found.
• Youza-youza incense to conjure up the dead...
• Perhaps the dead of their injuries.
• Between the dead ref and the dead judge.
• The dead can't harm the dead.
• This programme is not only an affront to the memory of the dead but, even worse, reduces the dead - and human existence in general - to a marketable commodity.
• Because when you think of the dead the dead can hear you.
• When the living think of the dead - the dead can hear their thoughts.