Two men have been jailed in England for their parts in the hacking of TalkTalk in 2015, which cost the British telecoms company an estimated £77 million (~ US$98.5 million). TalkTalk has already been fined £400,000 (~ US$512,000) for having inadequate security procedures.
https://www.notebookcheck.net/Two-men-imprisoned-for-their-involvement-in-the-2015-TalkTalk-hack.364236.0.html