Future Proof

First verse is about being at a border checkpoint. passport photos, reinforced glass, etc. 'Elastic past, empty pockets' = somebody with a flexible history i.e. fake passports, no luggage, etc.

Then we get the reference to drugs.

Then what I interpret as police checking for drugs. Maybe not so clear-cut here, but I read it as: "seperate the leper" = seperate the drug trafficker from the rest of the passengers "hungry ghosts" = police searching hungrily for a drug bust? maybe? "another imprint, in borrowed clothes" = borrowed clothes definitely evinces the whole falsified past thing mentioned before, presumably this would be the one with drugs. imprint = drugs, or concealed drugs?

then more drug references.