I was just thinking about this guy last night, and woke up to see that Catalin Cimpanu has an update on him:
The man is the hacker known as BestBuy, also known as Popopret. German authorities have not released the man’s name but referenced him under the nickname Spiderman, which the hacker utilized in registering domains names that he used in hijacking and controlling Deutsche Telekom’s routers.
Read more on BleepingComputer.
It appears that Brian Krebs’ identification of “BestBuy” as “Daniel Kaye” may be correct. In one of the German articles, the defendant was referred to twice as “Daniel K.” and he was described as a Brit with ties to both the U.K. and Israel.