You don't have a "legal right" to anything. They can close your account with our without cause. Your not going to gain anything by fighting them over this. Just get a new broker and move on, stop wasting your time.
In this case: 1) There is no foreign account; the account has been established and well-funded in the U.S. by a U.S. citizen, for 5 years. This citizen is entirely law-abiding and acting in good faith. Nothing "wrong" in any way has been done with this account other than what is legitimate and normal procedure for account access setup. No "warnings" were ever issued suggesting impropriety or pending termination. 2) There is a correctly established alternate login for the account, and no concerns were expressed as to this alternate login. IB provides for alternate logins for the purpose of legally (with Power of Attorney) delegating privileges, such as trading privileges to a third party who may be, for example, trading on your behalf. This is completely legitimate and an important feature of Account Maintenance. This suggests, in fact, that IB can and is prepared to terminate anyone, at any time without recourse, and not be required to state any reason for it. This is not my opinion; it appears to be a fact. I'll avoid expressing my opinions in this matter.
The fact that the account remained for 5 years, and just a couple of months ago, an alternate login was created for the purpose of allowing a non-U.S. resident to trade the account, is suspected as being the reason for the termination. The trader received no indication that there was a problem, and would certainly revoke access to remedy the problem, if the trader (the account owner) were given that option. That option to remedy the situation was refused. So, in fact, we do not know what the reason is, and the trader assumes or guesses that this must be the issue, despite the fact that IB refused thus far to discuss any reason for account termination. Not just account termination but termination of this trader's future possibility to retain an IB account at all.
It isn't just IB and it is not a suggestion or appearance. Any broker has the right to close any customers account at any time without recourse. There is no legal or regulatory requirement that any broker do business with you.
Actually, it's pretty stupid to give an offshore entity access to an account located here WITHOUT PRIOR APPROVAL. Verdict: 2 dumb to trade, if not too dumb to breath
Has anyone else been given the boot by IB ? Like for example because they were complaining too much ?
Verdict: Jumping to conclusions without knowing all of the facts. Maybe the off-shore entity is a family member, business associate or some other trusted entity.
Some guy on the Oanda message boards got the boot for talking smack about that broker. His account was closed and his money was returned (without his asking). He was very loudly raising concerns about Oanda's financial health and starting to cause a panic. The finally pulled the plug on him for "yelling 'fire!' in a crowded theater". They were very up front about it and it seemed reasonable, especially since the guy was a general douche bag anyway.