Some referred to receiving "ghost texts." The texts appeared to be sent or received from mobile phones with various operating systems and a wide range of carriers, including Sprint, T-Mobile, AT&T and Verizon.
Third-party text platform Syniverse said that regular IT staff maintenance resulted in 168,149 previously unreleased text messages being sent to subscribers from several mobile operators.
"We apologize to all who were affected by this occurrence," William Hurley, Syniverse's chief marketing and product officer, said in a statement. "While the issue is resolved, we are reviewing our internal procedures to ensure this does not happen again, and are actively working with the customer team to answer any questions they may have."
In a statement, T-Mobile stated that it was a third-party vendor problem that was resolved but did not provide further information. Sprint and AT&T did not immediately respond to a request for comment. Verizon declined to comment.
Many users believe that only their carrier and intended message recipients have access to their texts. But the ghost text event reveals a more complicated infrastructure.
Jon Callas, a senior technology student at the American Civil Liberties Union, said text messaging technology is "an incredible mess of software," where several intermediary parties stand between users and carriers. This structure has the potential to create a variety of privacy and security issues when a third-party vendor encounters errors or compromises their data.
Tasia Bass, a doctoral student at Michigan State University, says she received four texts in the middle of the night, while others reported receiving texts from her. She said she shared her story on social media in part to make sure she "wasn't crazy."
Samantha Majorczak, an Arizona-based treasurer and college student, said she received a text that said "How is your day going? " from his father, who died in March.
"I immediately began to cry," Majorczak said. "He used to text me every morning, and after eight months without any messages, I was in complete shock."