Rep. Adam Schiff (D., Calif.) told Face the Nation's Jon Dickerson Sunday that Hillary Clinton's private email server was a mistake and created an "unnecessary vulnerability" when it comes to national security.
"Using a private server was certainly a mistake and certainly the secretary's acknowledged that. Using any kind of personal server, whether it was her own private server or a commercial personal server, adds a security vulnerability," Schiff said.
Schiff said that even the government's own dot-gov server has been breached but said he was unsure if there was any breach of Clinton's private server.
A Romanian hacker called Guccifer claimed that he effortlessly had hacked Clinton's server and noticed that there were other IP addresses on at the same time.
Guccifer said that he did not think that there was anything of interest on Clinton's server but was not really paying attention.
In June, it was reported that Russian hackers had gained access to the Democratic National Committee's servers and to the database that contained all of the opposition research on Republican presumptive nominee Donald Trump. The hackers were also able to read DNC emails and chat traffic.
"The reality is none of these servers are immune from cyber attack. You have to defend them the best you can and the best practice is obviously to use a government server at all times and make a lot of improvements to those servers," Schiff said.
The FBI conducted an interview with Clinton on Saturday that lasted three-and-a-half hours, signaling that the federal investigation into Clinton's private server may be coming to a close.