Babies and blankets

I was scrolling thru facebook when I saw the below title. After reading the woman's original Facebook post about losing her baby, my heart went out to her. I can't even imagine discovering your baby like that... However, I also saw many people saying things like, "oh I never knew, no more blankets in my baby's crib!"

This surprised me. While I don't have a baby, I had heard about not leaving blankets in baby's crib for this very reason. Thoughts? If you have/had a baby, do/did they sleep with a blanket?