Most of my ideas are pretty weird, one that I had in mind but cant think of how to run it would be.

a war within virtual reality, Semi-Solipsistic Individualists versus Realist Collectivist.

Another idea is Temporal Technology is widespread allowing people to communicate with themselves in the past, while people are destined to send the message, the reason behind the message might change...and it might be sent by someone else using your phone. The plot would involve terrorists who will destroy the time machine, or perhaps the government will make up the destruction of the time machine. Time travel roleplays are hard to do.