Although DOJ has been using malware for nearly fifteen years, it never sought a formal expansion of legal authority from Congress. There has never been a Congressional hearing, nor do DOJ/FBI officials ever talk explicitly about this capability.
The Rule 41 proposal before this advisory committee was the first ever opportunity for civil society groups, including my employer, the ACLU, to weigh in. We, along with several other groups, submitted comments and testified in person.
Our comments can be seen here [3,4]. Incidentally, it was while doing the research for our second comment that I discovered that the FBI had impersonated the Associated Press as part of a malware operation in 2007 [5].
Ultimately, the committee voted to approve the change to the rules requested by DOJ. In doing so, the committee dismissed the criticism from the civil society groups, by saying that we misunderstood the role of the committee, that the committee was not being asked to weigh in on the legality of the use of hacking by law enforcement, and that "[m]uch of the opposition [to the proposed rule change] reflected a misunderstanding of the scope of the proposal...The proposal addresses venue; it does not itself create authority for electronic searches or alter applicable statutory or constitutional requirements."
[1] http://www.nytimes.com/2016/04/14/technology/fbi-tried-to-de...
[2] https://www.washingtonpost.com/business/technology/2013/12/0...
[3] https://www.aclu.org/sites/default/files/assets/aclu_comment...
[4] https://www.aclu.org/files/assets/aclu_comment_on_remote_acc...
[5] http://bigstory.ap.org/article/23f882720e564b918d83abb18cd5d...