Beware, lawmakers who protect their billionaire buddies. Meryl Streep isn’t having any of that.

“The people who are doing it have to be spanked,” she says, smacking her hands together. “It doesn’t stop until they feel they can’t.” The 70-year-old acting legend with a record 21 Oscar nominations (and three wins) stars – and educates the masses – in director Steven Soderbergh’s experimental Netflix dramedy “The Laundromat” (in theaters Friday in New York and Los Angeles, streaming Oct. 18). Based on the 2016 Panama Papers leak, the film uses intertwining stories and well-known actors to impart real-world lessons about tax avoidance, insurance fraud, shell companies, bribery and other financial shenanigans employed by super-wealthy folks to hang on to their cash flow. Streep’s character Ellen loses her husband (James Cromwell) in a vacation tragedy on New York’s Lake George that takes the lives of 20 tourists (a disaster that happened in 2005 in real life). When financial restitution doesn’t come, the retired widow launches her own investigation into shady schemes that lead to the two Panama City lawyers, Jurgen Mossack (Gary Oldman) and Ramon Fonseca (Antonio Banderas), at the center of the true scandal.

“She’s just trying to find her way through it,” Streep says of her character. “It’s just unfair. And sometimes that gets in the craw of people, especially if it’s personal. And that’s always the way people are most motivated, (like with) the gun debate: It’s people who’ve lost children, those are the people who move the needle and really stay with it when everybody else has moved on to another subject.” With “The Laundromat,” Soderbergh wanted a way, “preferably something poppy and fizzy,” to keep viewers entertained through dense material. And the combination of Streep’s activist public persona with her talents became a crucial part of the film. “We didn’t have a plan B,” Soderbergh says. “It was like, ‘Well, I hope she’s in a really good place when she gets this email because this is it. I don’t know what the other move is here.’ ” Streep herself was pretty knowledgeable – and a little peeved – about the Panama Papers. What surprised her delving in more with “The Laundromat” was how innocent folks are in jeopardy because of such practices. For example, poor people could be counting on money from a pension fund that might be invested through illegal entities. “What’s happened is that people who make the laws are funded by the people who are benefiting from the system. So nothing will ever change,” Streep says. “There’s a collusion of wealth that is self-protecting and our politics aren’t up to the job of policing it. The only way to fix it is to demand transparency and to demand your politics be cleaner.”

Streep thinks change can happen, pointing to Mayor Michael Bloomberg’s 2003 smoking ban in New York. “Bloomberg said, ‘You know what? You can’t smoke in New York City anymore. Anywhere. In any restaurant. And you can’t even go out on the sidewalk because it stinks up the sidewalk,’ ” Streep recalls. “Everybody thought it was impossible, a draconian thing. No, actually, laws work and if they’re enforced, they work and people are better off for them. So why can’t we do this?” Much more positive for Streep are the “women stories” being told on the film-festival circuit, and she calls her next project, director Greta Gerwig’s anticipated “Little Women” (in theaters Dec. 25), in which she plays Aunt March, a “masterpiece.” But she’s also taking a walk on the streaming side. In addition to “Laundromat,” Streep stars alongside Nicole Kidman and James Corden in the upcoming Ryan Murphy Netflix musical “The Prom,” based on the Broadway show about aging stage stars who help a lesbian teen when she’s banned from bringing her girlfriend to the prom. And Streep teams with Soderbergh again for the comedy “Let Them All Talk,” which debuts on the new HBO Max streaming service launching next year; it features Streep as a celebrated author and Lucas Hedges as her nephew, and was filmed entirely on the Queen Mary.

Wherever her work is seen, the actual job never changes for Streep: “The thing itself is what I love, the doing of it, then I hurl all my trust on the lap of the editor, writer, director and producer to put it all together and make sense of it.” But she’s glad “The Laundromat” will be on Netflix for when someone feels they need a lesson about real-world chicanery. “It will reach people who would not seek out a theater to go see maybe this particular subject matter. Or if they think, ‘Eh, it’s here. Let’s see what that is,’ that’s great,” the actress says. “That’s exciting to me, reaching into a demographic that was impenetrable before.”