I have the 360 version, and after playing about 4 hours (ingame) and 34 matches of TDM...it says I have over 10,883 kills and 5824 deaths. A few of my friends' are way too high too. And no, none of them have done glitch lobbies or anything.
 
This isn't even close to correct obviously. I'd guess that I'd have like 500-600 kills so far, maybe.  
 
The filter is on the default "friends / weekly," but when I change it to "friends / all time" I don't show up on the chart, and only 1 of my friends does. 
 
Is the weekly thing strangely estimating what your average will be for the week or something? Or is it just plain broken?  
 
All my other stats seem correct (weapon kill counts etc.) so it's just confusing me. Just wanted to make sure I'm not the only one with this issue.

Only the leaderboards are widely incorrect for me. Says I have 12,000 kills or something when I have around 689.

" @REIGN: Are you sure you're checking the correct menu you unlock when you get to level 13? "

I'm beginning to think that it's for some reason getting your daily data and multiplying it by 7 for some odd reason. That's my only guess so far.  
 
I still can't for the life of me figure out why only one of my friends shows up on the "all-time" leaderboard-- which for some reason seems to be reporting his score correctly. 
 
The guy on my list who is level 31 and has 32,363 kills and 20,812 deaths is the only one who shows up on my "all-time" leaderboard... but with 834 kills / 542 deaths. 
  
Who knows, maybe this will all get fixed once we get past week 1.