Former CitrusByte leaders sue S4 Capital over withheld escrow funds and shares

Brady Brim-DeForest, William Jessup and David Kullmann, who previously ran CitrusByte, sued S4 Capital in Delaware Superior Court, asserting that the advertising group has kept at least $7 million in escrow and delayed the delivery of stock tied to the 2022 purchase. Their filing describes a “campaign of obfuscation and delay” by S4, which they say used unfounded arguments to sidestep payment obligations. The suit also claims S4 settled a March 2025 lawsuit by former CitrusByte chief commercial officer Yoav Cohen without obtaining the consent required by the original acquisition agreement, thereby shifting costs to the plaintiffs.

While S4 declined comment and has not filed a legal response, the dispute underscores friction in Martin Sorrell’s rapid-growth model that relies on cash, equity and earn-out structures. S4, founded in 2018 after Sorrell left WPP, has seen its stock tumble roughly 94% from its 2021 peak and is currently cutting costs after a challenging period for its digital-marketing business.