Pellet Dodge relays your Display Name and Endless Mode High-Score for Endless Mode Online Leaderboards for your specific platform's Leaderboard service that you're running PD on. Your score will automatically be submitted after an Endless Mode run for convenience. You can opt out of this by either ticking the box in Online settings, or by being offline.
When you report someone, your Display Name will be shared with us to avoid false reports, as well as the one being reported's Display Name, the reason for the report, and whatever's being reported.