Calling it a small patch, Ubisoft has announced that Watch Dogs 2 update 1.09 is now live on PlayStation 4, and will be available later this week on PC and Xbox One.
According to the patch notes, the main purpose of 1.09 is to prepare Watch Dogs 2 for some upcoming updates, but it also brings several stabilization, performance, and bug fixes. Additionally, the .50 Cal sniper rifle was nerfed and the World Map exploit was fixed:

YourBoySerge Nerf ? This .50 Cal sniper rifle has been the subject of some debate in the community, and is considered to be overpowered in online play. In this patch, we?ve reduced the number of rounds in the magazine from 6 to 1, and we will continue to monitor and balance this beasty rifle.
World Map/Online Invasion Exploit ? Fixed an issue where players could help detect the presence of an invader in their session using an exploit the World Map.
Asked about the feedback players provided regarding Online Invasions, the Watch Dogs Twitter account replied, “This is a minor patch that addresses other things. We are still reviewing PvP feedback and gameplay data.”
In an interview with Game Informer, Senior Producer Dominic Guay was asked if the team ever considered removing guns. As Guay explained, they kept guns in Watch Dogs 2 to give choice to players:
It is true that Marcus, the character, would not generally use lethal approaches. You do not see him handling guns or shooting people in [cut-scenes] or in any forced narrative...