Chicago Tribune moves to compel evidence in Perplexity AI suit

Motions to compel and seal are standard procedural mechanisms in intellectual property litigation, particularly in cases involving proprietary technology. Historically, disputes over digital scraping and copyright have frequently stalled during discovery when defendants resist producing backend logs, arguing that such data reveals trade secrets or imposes undue burden. Precedent in web scraping litigation establishes that plaintiffs must demonstrate specific relevance before courts order production of technical infrastructure details. Concurrent motions to seal typically accompany these requests to balance transparency with commercial confidentiality. In AI-specific copyright cases, this pattern has emerged as plaintiffs attempt to distinguish between lawful indexing and infringing reproduction, requiring granular technical evidence that defendants often classify as core IP. The procedural friction observed here mirrors earlier disputes where courts had to develop new standards for evaluating the proportionality of discovery requests targeting machine learning systems, balancing the plaintiff's need for proof against the defendant's interest in protecting algorithmic architecture.

On November 3, 2026, the legal dispute between the Chicago Tribune and Perplexity AI entered a critical procedural phase as the plaintiff filed multiple motions aimed at compelling discovery and sealing specific case materials. According to court filings tracked by automated legal monitors, the Chicago Tribune submitted a formal motion to compel discovery (Doc #69) against Perplexity AI in case #CL71996467. This filing represents a significant escalation in the pre-trial process, indicating that the news organization believes Perplexity has failed to adequately respond to prior requests for evidence regarding alleged copyright and trademark infringement. The motion to compel suggests that voluntary cooperation during the initial discovery period was insufficient or contested, necessitating judicial intervention to obtain documents or data deemed essential to proving unauthorized content utilization.

Simultaneously, the Chicago Tribune filed a second, separate motion to compel (Doc #67) on the same date. The existence of two distinct compel motions filed within minutes of each other implies that the discovery disputes are multifaceted, potentially involving different categories of information or separate sets of interrogatories that Perplexity has resisted. In complex intellectual property litigation involving AI systems, such bifurcated disputes often arise when plaintiffs seek both technical backend data—such as crawling logs, model weights, or prompt engineering documentation—and business-side communications regarding licensing strategies or fair use analyses. The dual filings indicate a broad-based disagreement over the scope of permissible inquiry into Perplexity’s operations.

In addition to seeking evidence, the Chicago Tribune also moved to seal specific case materials (Doc #68). Motions to seal in AI copyright litigation typically accompany motions to compel when the requested discovery involves proprietary trade secrets, sensitive user data, or confidential settlement negotiations. By requesting protective sealing concurrently with compulsion, the Tribune appears to be anticipating that the evidence it seeks may contain highly sensitive information that Perplexity would argue warrants confidentiality. This procedural maneuvering demonstrates an awareness that the battle for evidence will likely involve parallel arguments regarding privacy and competitive harm. A certificate of service (Doc #70) was also filed, confirming that all opposing parties were properly notified of these aggressive procedural steps.

The underlying lawsuit alleges that Perplexity AI infringed upon the Chicago Tribune’s copyrights and trademarks through unauthorized content utilization. While the specific factual allegations remain subject to adjudication, the current procedural posture shifts focus from the merits of the claim to the mechanics of proof. Discovery is the phase where abstract legal theories about AI training and inference must be grounded in concrete technical realities. If the court grants the motions to compel, Perplexity may be required to disclose internal architectures or data handling practices that have previously been opaque to outside observers. Conversely, if the court denies or limits these motions, it could signal judicial skepticism regarding the relevance or proportionality of the Tribune’s evidentiary demands.

The timing of these filings—all occurring within a five-second window on November 3, 2026—suggests they were part of a coordinated legal strategy rather than reactive responses to new developments. This batch-filing approach is common when counsel anticipates that multiple procedural hurdles must be cleared simultaneously to maintain litigation momentum. For Perplexity AI, these motions represent a test of its defensive posture; the company must now articulate why certain discovery requests are unduly burdensome, irrelevant, or protected, while potentially negotiating the terms under which sensitive technical disclosures might occur. The outcome of these motions will likely set the evidentiary boundaries for the remainder of the case, determining whether the Tribune can access the forensic data necessary to substantiate its claims of unauthorized scraping and reproduction.

The Chicago Tribune risks inability to prove infringement without compelled technical evidence, potentially undermining its copyright and trademark claims. Perplexity AI faces exposure of proprietary crawling, indexing, and generation systems if discovery is ordered, which could reveal trade secrets or create precedent for future AI litigation. The magnitude centers on evidentiary access rather than immediate financial liability; however, discovery rulings here may influence dozens of pending AI copyright cases awaiting similar procedural determinations. Both parties invest significant legal resources in this phase, with outcomes shaping settlement leverage and trial viability.