A group of anonymous plaintiffs who filed their taxes online in 2020 using H&R Block has sued Meta, accusing the company of violating users' trust and privacy.If you'll recall, a recent Markup investigation revealed that H&R Block, along with other popular tax-filing websites like TaxAct and TaxSlayer, have been sending users' sensitive financial information to Meta through its Pixel tracking tool.Pixel is a piece of code companies can embed on their websites so they can track visitors' activities and identify Facebook and Instagram users to target with ads.The tax-filing services had already changed their Pixel settings to stop sending information or had been reevaluating how they used Pixel by the time Markup's report came out.The plaintiffs acknowledged in their complaint (PDF, courtesy of The Markup) that Meta does require businesses that use Pixel to "have lawful rights to collect, use and share" user data before providing the company with any information."