As Rad said, I tend to think of the Dúnedain in the books as sort of a ' Shadow Ops group. They kept their identities and missions as secret as possible more out of necessity than anything else.
From The Council of Elrond-
'If Gondor, Boromir has been a stalwart tower, we have played another part. Many evil things there are that your strong walls and bright swords do not stay. You know little of the lands beyond your bounds. Peace and freedom do you say? The North would have known them little but for us. Fear would have destroyed them. But when dark things come from the houseless hills, or creep from sunless woods they fly from us. What roads would any dare to tread, what safety would there be in quiet lands, or in the homes of simple men at night, if the Dúnedain were all sleep, or all gone into the grave?'
'And yet less thanks have we than you. Travellers scowl at us, and countrymen give us scornful names. "Strider" I am to one fat man who lives within a days march of foes that would freeze his heart, or lay his little town in ruin, if he were not guarded ceaselessly. Yet we would not have it otherwise. If simple folk are free from care and fear, simple they will be, and we must be secret to keep them so. That has been the task of my kindred, while the years have lengthened, and the grass has grown. '
Today is a good day for Pie.
Do not meddle in the affairs of Burglars, for they are subtle and quick to shank you.