"Of any country I've visisted[sic], Uber is the least necessary in Colombia. The taxi system is extremely fair and safe, albeit cash only right now. It's highly regulated and you can count on predictable, transparent, fair rates."

This is only because of Uber. They were terrible before Uber appeared.

This is the problem I see. Now taxis have no reason to be fair and safe anymore.

A common trick is a button behind the wheel, that can be activated without the passenger noticing, and it just makes the meter jump up. Well timed use can make the rate double of what it should be, without suspicion.

Very interesting anecdote about Uber drivers in Medellin. I guess it is the right strategy to avoid another Uber car burned by angry taxi owners.