Lawyers for Donald Trump's transition team have sent letters to members of congress accusing special counsel Robert Mueller of illegally obtaining emails belonging to transition team officials from the General Services Administration.

The GSA hosted the transition team, using their devices and facilities. But the lawyers claim the ownership of private communications belongs to the individuals on the transition team and not the GSA, who turned over thousands of emails to Mueller's investigation.

Update: Mark J. Fitzgibbons comments:

The Trump lawyer raised the 4th Amendment, but that won't fly since the information is on government servers and in government possession.  This is somewhat similar to the issue Gorsuch raised in the Carpenter cell phone information case, but that information was in private corporate possession, not government possession.
    
Conservative outlets and social media were yelling foul.  A problem here is that the independent counsel law can be interpreted to allow pursuit into more than the initial matter being investigated if the independent counsel believes there is something to pursue.
    
Very clever move by Mueller.  Even the privileged legal communications may not be protected from him since they are stored with the GSA, although that may need to be resolved in court.
    
 As I wrote for The NonProfit Times this month, never discuss legal issues or even ask legal questions in email.  One innocent question in an email put Arthur Andersen out of business.
 

CNN:

The lawyer, Kory Langhofer, wrote to leaders of the Senate Homeland Security and House Oversight and Government Reform committees because he said the General Services Administration, which supports presidential transitions, "unlawfully produced" private materials of the transition although the GSA "did not own or control the records in question."

Langhofer wrote in the letter the Special Counsel's Office "was actively using those materials without any notice" to transition officials.

The letter states there were two other occasions where the Special Counsel's Office did not notify transition officials that their records had been requested or received.

Peter Carr, a spokesman for Mueller, responded to the accusations early Sunday.

"When we have obtained emails in the course of our ongoing criminal investigation, we have secured either the account owner's consent or appropriate criminal process," Carr said.

GSA Deputy Counsel Lenny Loewentritt disputed a claim by Langhofer that the GSA's general counsel had agreed in June that any requests for transition records would go to the Trump campaign, BuzzFeed News reported Saturday night.

Loewentritt said transition officials were told that "in using our devices," materials "would not be held back in any law enforcement" requests. He added there was a series of agreements between the transition and GSA for using its goods and therefore there was no expectation of privacy.

Langhofer's letter also states that Special Counsel's Office had obtained transition laptops, cell phones and at least one iPad after the FBI requested them of career GSA staff without a subpoena.

The letter also says a representative of the Special Counsel's Office told transition officials it did not recover any documents from that hardware, but failed "to disclose the critical fact that ... the Special Counsel's office had simultaneously received from the GSA tens of thousands of emails."

"The materials produced by the GSA to the Special Counsel's Office therefore included materials protected by the attorney-client privilege, the deliberative process privilege, and the presidential communications privilege," the letter maintains.

Why is Mueller investigating post-election activities of Trump's transition team? Contained within those emails are extremely sensitive communications about personnel and other details that should be irrelevant to Mueller's collusion investigation. Why is he investigating how the Trump White House was formed and developed?

Then, there's this:

The sources say that transition officials assumed that Mueller would come calling, and had sifted through the emails and separated the ones they considered privileged. But the sources said that was for naught, since Mueller has the complete cache from the dozen accounts.

William Jacobson explains the implications:

This is sure to escalate the situation, and has all the appearances of impropriety by the Special Counsel’s office. We will update as more becomes known.

Once again, however, this shows how Mueller is going beyond his mandate and investigating post-election politics and political decisions of an incoming administration.

Perhaps this is why rumors started swirling on Capitol Hill that Mueller would be fired.

Mark Fitzgibbons believes the document grab by Mueller may be legal:

Unfortunate, but this document grab by Mueller may be legal under the broad special counsel statute. And due to GSA's role pursuant to presidential transition acts of 1963 and 2015, this doesn't appear to be a 4th Amendment violation. But #Mueller keeps overplaying his hand.

— MarkFitzgibbons (@MarkFitzgibbons) December 17, 2017

I think the special counsel can do just about whatever he wants to. That's the whole point of creating the office in the first place so his legal powers are extraordinary.

But here we have transition officials perfectly willing to cooperate with Mueller only to find that he has steamrolled them, seizing what the Trump lawyers believe to be privileged communications - communications that, by definition, have nothing to do with Mueller's investigation of collusion between the Trump campaign and the Russian government.

Obviously, Mueller is finding the collusion angle a dry hole and is casting about for something - anything - he can charge the president and his people with. Perhaps be believes he can find illegality by Trump transition  officials and then "flip" them to give up what they know about Russia and collusion. If that's the case, it is a sign of desperation on Mueller's part.

Mueller is ranging far afield of his original mandate with no sign he plans to rein in his investigation. Democrats seem perfectly happy to support an out of control special counsel but Trump and the Republicans are going to start pushing back. You have to think a showdown is coming which almost certainly won't end well for Mueller.