If you text back, they reply "hey, I was wondering if you could pick up some gift cards for a needy family I'm working with. You don't have to bring them over, just text me the numbers on them and I'll make sure they get them."
The gift card scam has been around for years, I see them all the time. Usually it's someone has their address book compromised and then everyone in it gets a gift card request. Just got one the other day.
The newer gift card scam, that I'm surprised took this long to surface, involves tampering with the cards so when you buy it and it gets loaded, the scammer immediately empties it before the recipient ever sees it. A throwback to the old 1970's scam that people would replace the deposit slips at the bank with ones encoded for their bank account. When you made a deposit and used a bank's deposit slip, the numbers were already encoded so the bank just send them through and your money went with them!