With all the messaging apps available now, it is really hard to say who is legit or not and not just on telegram. Even those gals who provides video calls before you meet, it is not guaranteed that you will get that person. So the best next thing one can mitigate a bad transaction is do as much “research “ as possible. My experience is that the legit one’s have email addresses and after initial consultation they will provided you with a messaging app. But the again, it is still a jungle out there. Hit and miss is always a possibility. In a way, that is what makes it exciting, the “hunt”.
