While not the Greatest thing, it would seem there is a need for this among other people. By Following these steps you will need to click the failed to Log-In popup when it shows in game until you replace the file.
1. After making sure that you are not actively running Vindictus, Open your Start Menu, then click on Computer
2. Double Click OS: C, then navigate through the Nexon Folder, and in to your Vindictus Folder, then open en-US.
3. Locate your NMService within the en-US folder. This is the Application that allows those on your guild and friend list to see what you do as well as communicate.
4. Remove the file from the folder, I personally drag it to my Desktop until I am finished with what I am doing.
5. Proceed to do whatever actions you did not want those who have your contact information to see.
6. Close Vindictus and replace NMService in your en-US Folder, this will reinstate any people on your Friends list, as well as the ability to use your Guild Chat, and Friend List Functions.
Credit @BloodyLord7777 for File name.