Exposing door hinges to outside-any security issues?

[aries31]

I have four exterior doors and I am planning to have 3 of them open outside the house (mostly backdoors). These will be steel doors with good quality hardware.

The hinges will be exposed from outside. I am told this is a poor security practice. Is this true? Are there any problems if the hinges are outside the house? Can theives easily dismantle hinges?