I can confirm to you all as of now that Alex was taken away on August 9th. (Edit, I can only confirm according to him that this is what happened.)
I'm going to be really honest and tell you that I can not confirm why he was specifically taken away. His final post was that he was literally being taken to jail and he would see everyone whenever. Now, that seems pretty cut and dry yes, but when you're reading Alex's posts you really need to understand that he is incredibly insane. He had a pretty powerful schizo break down on the 8th, and it's a bit hard to distinguish the fact from fiction. So while I am reading his actual own words here, I'm willing to say to you all that alex is not a reliable narrator of his own life.
It APPEARS that Alex directly broke his restraining order early on the 9th, by sending a letter to kate. The letter appears to been half love letter, half spergout about the kiwifarms. Alex calls the letter "His death warrant" He goes silent for several hours and which I assume to be him delivering the letter, and then his next posts are presumably from the back of a police vehicle. He says bye to everyone and he hasnt said anything since. Alex posts regularly 24hours a day every day, and hasn't posted or been active since on any of his accounts, which i'm fairly certain means this is legit since alex doesn't have the capacity to get off the internet on his own.