Did you?
Despite the fact that the Sanders campaign staffer initially lied about breaching Hillary's data, Bernie himself lied when he said his campaign did nothing with Hillary's data, which is why Politifact gave him a "Mostly False" in that article.
What did they do with the data?
The article itself states there's no way to know if they copied or printed what they queried.
The "mostly false" doesn't even make any sense in the context of Sanders' claim. He said they didn't "go out and take" any info, Politifact says "From all accounts, it is true that the Sanders campaign did not attempt to break into the voter data of a rival campaign" so what exactly is false here? They accessed data for less than 2hrs and the guy who did it was fired and two other staff members were suspended.