[kyberias]

I don't see any randomness in the implementation. It seems to be taking users in the sequence that the github users API provides.

[idnan]

But you are not going to see the same profile again and probably you don't know them. So it's random for you. :)

[brudgers]

"Arbitrary" is probably more consistent with the mathematical rigor some people might expect. On the other hand, little in computing is random rather than pseudo-random.

[tyingq]

Seems easy enough to get the upper bound id...

https://api.github.com/search/users?q=created:%3E=2016-04-16... (backing off the date if needed)

I would prefer random over ascending.