Do dropped items in Ingress decay?

If I drop an item in Ingress, will it be there until someone picks it up, or is there a chance of it decaying? I realize the danger of someone unexpected coming along and picking things up, but does anyone know if items will eventually disappear on their own?

I have had a feeling they do, but cannot confirm it 100%, but it seems I was wrong, after Christmas I am going to check items dropped in November if still there I would say that dropped items do not decay

Right now I can confirm dropped items stay alive for at least 14 days.

I am dropping keys and media files I don't need at difficult to access locations (high speed train rails) and I am pretty sure they won't be picked up. I will keep testing it.

Update 1: 8 days decay free.

Update 2: checked on a very old dropped media item 2 weeks ago and still there

Update 3: All items dropped before 24.12.2012 decayed - removed or maybe picked up, but this is highly unlikely

On Jan 9th, Niantic leaked a document suggesting that the next update will make dropped items have a 12 hour lifespan.

Source: http://www.nianticproject.com/?id=sc208b

"Objects dropped out in the world will lose cohesion and disintegrate in approximately 12 hours"