During Order of the Phoenix Harry gets regular insights into Voldemort's thoughts and feelings. He gets snapshots of where Voldemort is and what he's doing. These visions stopped during Half-Blood Prince because Voldemort was practising Occlumency.
"So tell me, Harry," said Dumbledore. "Your scar...has it been hurting at all?"
Harry raised a hand unconsciously to his forehead and rubbed the lightning-shaped mark.
"No," he said, "and I've been wondering about that. I thought it would be burning all the time now Voldemort's getting so powerful again."
He glanced up at Dumbledore and saw that he was wearing a satisfied expression.
"I, on the other hand, thought otherwise," said Dumbledore. "Lord Voldemort has finally realised the dangerous access to his thoughts and feelings you have been enjoying. It appears he is now employing Occlumency against you."
(Half-Blood Prince, Chapter 4, Horace Slughorn).
It seems that at this point Voldemort realises that giving his archenemy intimate access into his mind and his plans isn't such a good idea. Which makes it all the stranger when those visions start up again in Deathly Hallows. Why would he make himself vulnerable in this way?
In Order of the Phoenix, he uses his connection with Harry as a weapon, to trick Harry into going to the Department of Mysteries to retrieve the prophecy. Even though he also gives Harry unintended insights into his plans as well (such as when he interviews Rookwood) he is basically a step ahead of Harry. The connection serves a purpose.
In Deathly Hallows it surely serves no such purpose. It only makes Voldemort vulnerable. Because of the connection Harry is able to keep track of Voldemort's movements and plans, which hindered Voldemort on several occasions. Through the connection Harry was forewarned that Voldemort was on his way to Godric's Hollow and to Malfoy Manor. Through the connection Harry realised that Voldemort was obsessed with the Elder Wand, meaning that Harry could potentially have worked out its location and taken it before Voldemort got there. Through the connection Voldemort showed Harry that he was worried about his Horcruxes being discovered, and in the process revealed to Harry that the last Horcrux was hidden in Hogwarts. And through the connection Harry knew Voldemort was in the Shrieking Shack during the Battle of Hogwarts, allowing Harry to get Snape's last memory. Time after time, Voldemort exposed himself in a way he didn't during the previous book.
Was stopping Occlumency a conscious decision on Voldemort's part? What purpose did it serve?