Which credit card do you actually have?
Not as in maybe you aren't a member of Citibank Rewards, but just curious.
-Me
My guess is because there are a few Mc Donalds transactions, stemming off the back of the recent skimming fiasco.
Moral of the story: don't eat at Maccas
(although I have heard that the Angus burger was quite tasty)
Still you would think is your card had been compromised, they would have been more proactive in contacting you about the issue.