My opinon is, The 3 or so credit reporting agency dont report anything to the INS/homeland security.
But if your creditor wanted, i belive they can file a charge. Credit card fraud is considered a felony, please correct if I am wrong.
So this is the worst case scenario imho.
If they run a background check on you, a Felony would stick out like a Royalist in a sajha thread (just trying to liven up the mood, sorry if you didnt like it)
Also though, you Creditor will probably never know that your friend have left the country.
For a while, they will charge late fee on the account, then hike up the apr, they will probably come to the conclusion that your friend is not going to be paying up anytime soon. Then the will send out their dogs, aka the collectors.
They will naag your friend over the phone....alas your friend's phone is no longer in service. you will get constant mails. Depending upon where you borrowed and other factors...they will seize your friends house, car...if it was leased. The APR on your other cards and loans will go up.....
o but most of this might not apply to your friend...one piece of good news.
I usually dont like to break or potentially break any law like the next guy.
Depending upon the state your friend lives in...I would file for Bankruptcy!.
once again, just my opinions, hope it helped friend.