Outspoken Hollywood celebs had their social media accounts at the ready to tweet their opinions on Robert Mueller's testimony as the former special counsel appeared before two congressional hearings on Wednesday to discuss his investigation into Russian interference in the 2016 presidential election and the campaign of President Trump.

"Who's the Boss" actress Alyssa Milano transcribed a give and take to make her point. "Lieu: 'The reason you did not indict Donald Trump was because of OLC opinion stating that you could not indict a sitting president, is that correct?'

Mueller: 'Yes,'” she wrote.

Actor and activist John Cusack summed up the proceedings in just a few words: "Yup obstruction all day long - RT @joshtpm: This. Basically the whole thing."

Former "SNL" cast member Rachel Dratch was among the first to comment on the Mueller testimony, approaching the proceedings with a measure of dread tinged with hope: "The act of looking forward to the Mueller hearings as if anything will come of it feels like having lunch with an ex that you are hoping to get back together with."

Piper Perabo took a helpful tack, using her Twitter account to explain some terminology to her followers:

"OLC is the Office of Legal Council. It assists the Attorney General as legal advisor to the President.

OLC policy tells Mueller a sitting President can't be charged with a crime.

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So if a President commits a crime, Congress must use the power of impeachment. #MuellerHearing," she wrote.

Maria Shriver defended Mueller's delivery. "Could it be we are simply witnessing a man with deep integrity who is cautious with his words and that we are comparing his style to the way people scream and yell today? Could this be two different styles, two different generations?" she mused.

"Apollo 13" director Ron Howard urged viewers to make up their own minds. "#MuellerHearing I’m hoping this is widely viewed with open minds by all interested citizens and voters so we don’t have to depend entirely on pundits and social media for analysis," he wrote.

Yvette Nicole Brown took a jab at Rep. Louis Gohmert, R-Tex., to whom Mueller gave a curt response to a fiery question.

"No matter what I'm asked, for the rest of the summer, I'm only responding w "it's not in my purview," wrote comedian Kathleen Madigan.

"Attn: pundits: The impact of the whole Mueller investigation has less to do w/ this president than The Presidency, and what behavior we’re okay with down the line. The only worthwhile conclusions are ones in which you could swap Obama for Trump & still stand by them. Thanks," wrote actor James Van Der Beek.

"#MuellerTestimony #MuellerTime u besta b watching! I’m not playing!" John Leguizamo told his followers.

Mia Farrow directed a jab at Donald Trump very shortly after the testimony began, tweeting: "You have zero credibility. And soon it will be clear to all that you did in fact obstruct justice - at least 10 times."