Not much details in the original source:

> Additionally, companies in the technology industry own large numbers of patents, copyrights, trademarks, and trade secrets and frequently enter into litigation based on allegations of infringement or other violations of intellectual property rights. For example, on March 18, 2024, Nokia Technologies sent us a letter indicating they believed that Reddit infringes certain of their patents. We will evaluate their claims. As we face increasing competition and become increasingly high profile, the possibility of receiving more intellectual property claims against us grows.

https://www.sec.gov/Archives/edgar/data/1713445/000162828024...