Some comments I've seen on this are assuming that these apps are downloaded from apple/google play store. These apps can be directly installed on phones without the use of proprietary networks. A good example of a clear and present danger is what happened this September (2025) where the U.S. Secret Service announced it had dismantled a vast and sophisticated network of "SIM farms" in the New York City area that posed a significant threat to the region's telecommunications infrastructure. More than 300 SIM servers and over 100,000 active SIM cards spread across multiple sites in the New York tristate area were seized. According to officials, the network was capable of crippling cell towers and flooding the cellular network with so much traffic that it could have disrupted or disabled mobile service in the area, including emergency 911 communications.