How's my wreckless driving?
The Achievements are stating they were earned "Offline" the requirements are set to Online Xbox Live Gold Membership Participation, as the achievements were in some way Modded/Hacked we can't help you, as Hacking, Cheating or anything of the sort isn't discussable on the Bungie.net Public Forums, And never will be.
[Edited on 08.14.2010 7:58 PM PDT]