> How do you know?

A couple of lawsuits.

This is a matter of some urgency, a company that has its funds frozen can not trade and the knock-on effects are substantial (employees, taxes, invoices). So the courts should be easily convinced they need to move fast or the damage will be substantial. There are special procedures for such affairs and they tend to be heard within days.

> And in the meantime, your money is frozen by the bank.

That could be a very short time. But then again, I am not a lawyer, merely the frequent consumer of lawyers' time.

> Not a lot of lawyers will be happy to work for free in the hope you will get access to your money eventually to pay them.

Any lawyer unwilling to take your case is not worth doing business with anyway since they tell you effectively they won't be competent enough to see this through to a speedy conclusion.

> And forget about not having money to hire a lawyer.

Yes, I will happily forget about it since it is not an issue.

> You don't have money to pay salaries (or a salary if you are a one person company), bills, rent, mortgage.

This is exactly why you have a case and one with an urgent component.

> You have survival things like paying your rent so you don't end up on the street as top priority while your bank account is frozen.

Well, you will so that's why my suggestion to re-route any outstanding invoices to a new account pronto to avoid getting caught.

> I think you underestimate how expensive lawyers are and especially for small businesses they really can't afford them.

I think you underestimate how many times I've used lawyers in the past and how important it is to know your way around the legal system as an entrepreneur. Sooner or later you will either sue or be sued and if that's your time for learning you are too late.

> Which is why there needs to be strong regulation / legislature to make sure banks cannot just freeze your money because their buggy anti fraud system flags your account for some bogus reason.

Likely this is exactly why the account is frozen in the first place. And which is why you need to play this by the book and without delay.

> At the very least they should be forced to allow you to withdraw some amount of money per month (2-3k) let's say while your account is in review, so you have money to pay your rent/gas/food and other basic cost of living expenses.

I'm pretty sure that is exactly the kind of thing a ruling would aim for, but again, going by my experience the bank will avoid going to court at any cost and will long before that point give you a one time option to withdraw your money and move your business elsewhere. Now what happens after that is an annoying problem to have because it may very well be that the business or one of its partners - and not the account - was flagged.

> Apparently they can just freeze your account and your money is gone perhaps for months. That's frightening.

It never was any different, it's just that with the terror and the drugs laws these things happen more frequently. Also, some businesses are much more liable than others to be used for money laundering / financing of crime / evading embargoes and so on and you really need to think ahead about stuff like this to avoid getting bitten by it.

Again, I'm not a lawyer but I have worked in banking - albeit long ago - and even in those days there were plenty of rules in place and I have used the legal system quite extensively and as far as I can see this case is not special or in any way lost before you've tried to fight.

It will cost some time and some money, the latter you may be able to recover depending on how the judge sees things, the former you will certainly lose. I would be extremely surprised if the bank actually let the case go to court and if they do that's a strong sign there is more to this than the OP is letting on so for now my money is on the bank folding at the first sign of serious opposition.