M.I.A. is a chart topping musician who started life as a Tamil refugee from the Sri Lankan civil war and has maintained consistently great messaging throughout her entire discography. She's more focused on revolutionary anti-imperialism and womens/ethnic liberation than explicit anti-capitalism but she fits that in too. She's never achieved the highest honour of an assassination attempt courtesy of the US State but she did get on the US no fly list and Oprah to call her "crazy and a terrorist" on record so that's got to count for something.

She started her career by getting a song explicitly stanning PLO and Tamil Tiger fighters on the radio and to the top of the charts in 2004 and is still going strong today. Absolute badass music and genuinely popular, her top video has 190 million+ youtube views and she regularly gets 10 million+ on her newer videos, and again, I don't think she's released a single video that doesn't center some form of radical messaging. She also personally directs or personally chooses the director of all of her music videos. Hard to recommend strongly enough.