Clients on Consulting portal

Hi Everyone, one quick info needed–how far can we believe that some of H1 b consulting firms publishing top clients directly on their website?? Please let me know

I am not sure how much big clients go around checking if someone is using their name.

In addition, if company has contract w/ vendor A who has contract w/ vendor B who has contract w/ consulting company C; you will see A, B and C all using client’s name on the website.

To take it w/ a grain of salt.