Square is holding funds

The company will let you do business for few weeks and then it will hit you with a large deposit on hold do to account verification. Why they do not verify their clients upfront???? I was under the impression that opening an account is completed after true verification of a company in question. If you do not do that, how can you protect the potential users???? I am thinking that by holding large deposit for few months they are making some money on some speculative transactions. Where are the funds????  The clients card is charge and we are not able to get the deposit.... Great business !!! Free Money!!!!