Just a brief analysis
Mr. Solano, from experience, says:
" they gave us a hassle with a photocopy and I had to get tough with the Police."
Also, he states, from what he's heard:
"don`t ever loose your it, I have heard it takes over a month to get a replacement, you can`t go back home without it ..."
So, you, the tourist, decide using your common sense.
I go with photocopy, driver's licence and lots of comments about how great Colombia is and how safe I feel thanks to them.