Is there no way you can prevent this? Can't you insist that they consume the host before they step away? What an abominable practice!
&&
While I was still teaching in a (nominally) Catholic school, my students and I attended a Mass at which one 9th-grade student started to walk away with the Host in his hand. The priest (a young, passionate man who tried very hard against all odds) chased after him and got the boy to consume the Host.
I am sure this kid meant no harm. It's possible he was not even Catholic, but I suspect that he was baptized RC and just never properly taught. It's amazing how many of these so-called Catholic kids and their parents never attend Mass.
Lol! My Maronite pastor is bi-ritual (Maronite and Latin Rite). On those occasions when Roman Catholics attend the Maronite liturgy, should they step forward hands extended to receive the host, he gives them a quick education on the proper reception of the host in the Maronite Church - only on the tongue. When he says the Latin Mass, he has been known to chase down those communicants who do not immediately place the host on their tongues. He has also been known to lecture the nun who serves as 'chaplain' at a local Catholic hospital, on the proper distribution of consecrated hosts. He has turned into a thorn in their sides :-)