Why did Sheryl Sandbergs Facebook post begin an online discussion about grief?\r<br>\r<br>How did Pakistanis react to India catching the spy pigeon?\r<br>\r<br>What happened when Caitlyn Jenner joined Twitter?\r<br>\r<br>The answers to all those questions, and more trends of the week.\r<br>\r<br>SUBSCRIBE to BBC Trending: \r<br>\r<br>Like what you see? Follow us here:\r<br>BBC Trending blog: \r<br>Twitter: \r<br>Facebook: \r<br>\r<br>______________________________________________________\r<br>\r<br>Blogs mentioned:\r<br>A Facebook executives candid post about grief: \r<br>\r<br>Celebrities face criticism for transgender opposition: \r<br>\r<br>Pakistanis respond after spy pigeon detained in India:
