Because now on Twitter and Facebook they are using blasphamy as hate speech. As in, nothing is allowed to be said against Islam or Muslims. Of course anyone can say anything about any other race or religion. Censorship is rife.
Say for instance that I posted a link to a blog post about FGM being practiced in the UK by Muslims, that post would be removed, and I would maybe get a 7 day block from Twitter. But of course Ex-Muslims are now telling on that hashtag absolute truths about Islam such as "#wheniwasamuslim I was cut without my consent as a child".
No one is allowed to say things like Muslims drink camels pee, which is true by the way, but of course if an Ex-Muslim on that hashtag says that he/she as a child was forced to drink camels pee, Twitter are in a quandry, because how can they treat it as blasphamy when it's someone actually telling something about themselves. But the practicing Muslims are having a fit and want the hashtag banned.
Muslims don't want the world to know just how evil Islam is, as they lie through their teeth about it being a peaceful and loving religion to get converts from the west. They believe that if they can get just one convert then they are guaranteed a place in heaven regardless of any sins they might do.
Also don't forget that in about 13 countries leaving Islam is a death sentence under Sharia law, and unofficially it's a death sentence all over the world, including the UK. Every year here in the UK ex-muslims are being murdered by their family and friends for leaving Islam. Of course the state and media keep it quite in order for the British people not to start turning on migration.
Up until now, ex-muslims either go into hiding or pretend to still be faithful Muslims even to still going to Mosque and saying prayers 5 times a day because they are terrified of their friends and family. But one single Muslim on Twitter had the guts to start that hashtag and it bringing out all other ex-muslims. It's giving them courage to say they don't believe in Islam or Muhammad as being a real prophet.
They are being accused by Muslims of lying, of never beinng Muslim, of being trolls and setting up fake accounts just to tell lies about Islam.
So Twitter must be in a panic because all the truth of Islam isn't supposed to be told, it's supposed to be quashed by state, the media and of course by social media.
Even if you don't have a Twitter account you can still read the posts. So if you want to click on that hashtag and go read you can.