For a while there was almost no hand baggage allowed -- with very few exceptions for baby-related goods, some medication, travel documents, keys without electronic "fobs" and money/bankcards -- and that which was allowed went into plastic see through bags for flights between the UK and US. Basically, the above noted items wouldn't be permitted on a LHR-JFK flight for a few days. I don't know if that's the case not or now since LHR-JFK is one of those routes I've fortunately avoided these last few days.