Margaret Lyle defends consumer and mass tort class actions and represents technology companies in complex litigation and appeals involving intellectual property. She has successfully defended proposed class actions brought under common-law theories of fraud, unjust enrichment, conspiracy, products liability, medical monitoring, and toxic exposure, as well as under state and federal consumer statutes including the Fair Credit Reporting Act, the Magnuson-Moss Warranty Act, the Driver's Privacy Protection Act, the Credit Repair Organizations Act, and RICO. Her appellate representations in state and federal courts include SAS, Sercel, Experian, R.J. Reynolds Tobacco Company, and other industry leaders.

Margaret has defended Computer Sciences Corporation in class litigation over its insurance software, Interstate Battery in class warranty litigation, the Washington Division of URS Corp. in class litigation over New Orleans flooding following Hurricane Katrina, and Experian in class actions involving privacy, internet marketing, and consumer claims. She represented R.J. Reynolds Tobacco Company in more than 30 proposed class actions across the country, including cases of first impression in Nevada and Oregon, where the state supreme courts rejected a medical monitoring tort.

Margaret serves as a programming chair for the ABA's Class Action and Derivative Suits Committee and as editor for the ABA's The Woman Advocate. She has served on the panel of practitioner contributors to Black's Law Dictionary and was a founding director of Marshall Lawyers Care. A Dallas Bar Foundation Fellow, she is a member of Attorneys Serving the Community and has served on the boards of community arts and historical organizations.