As part of their ongoing effort to combat misinformation about COVID-19, federal agencies have issued warning letters to more than 150 companies. While companies know that a warning letter is serious and requires immediate attention, perhaps the greater challenge is what often follows: the so-called “piggyback” class action lawsuit.[1] And recently, plaintiffs’ attorneys have gone one step further: they have been filing “piggyback” class actions not against the company that received the warning letter…