At the end of the book Harry Potter and the Deathly Hallows, during his last standoff with Lord Voldemort, Harry went into a huge amount of expository dialogue with regard to the Elder Wand in front of what was probably hundreds of people who were following his and Voldemort's every word. Specifically, at the end, Harry declared and showed that the Elder Wand owed him its allegiance; what was also revealed was that Dumbledore was a previous owner of the Elder Wand.
This makes me wonder if Harry wasn't inviting himself to attack by other witches and wizards intent on gaining the allegiance of the Elder Wand and inviting Dumbledore's tomb to defilement again so that the said witch or wizard could actually gain possession.
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"You have a responsibility to consider all sides of a problem and a responsibility to make a judgment and a responsibility to care for all involved." --Ian Danskin