Think about it logically:
How far can the average person walk in one day?
Where would they rest and find lodging, eat, and use bathroom facilities?
How many days could they do this sequentially and what would the costs be?
How many pairs of shoes would it take?
All these things are not feasible as most would die on the journey. They have to have lots of money, time, health, and endurance and they are supposedly impoverished people. We are talking thousands and thousands of miles just to get to the boarder not including hundreds or thousands more once here. They have to be sponsored by some extremely deep pockets that have to have the support of the governments. Even a group of rich person would not lose that type of money unless they are being backed by tax payers through the governments.
We need to start arresting the sponsors.