There are so many exchanges, it is difficult to know which to sign up for.
Many want personal information, but can they be trusted.
This article lists many of them, and based on the survey results, the choices of who to trust with your data may be limited to just a few, based on their reporting 'performance'.
https://www.ccn.com/major-bitcoin-exchanges-accused-of-faking-volume-whos-trustworthy/