Switzerland recently added three names to its existing list of over 500 people and organizations suspected of Islamic terrorist activity, and thus barred from opening a Swiss bank account, or even entering Switzerland. This is all part of an effort by Switzerland to try and get away from being known as a hideout for dirty money. For centuries, Switzerland provided secret accounts, which tax-evaders, criminals and privacy minded people all used for their banking. There were other reasons, of course. Swiss banks have, for centuries, been noted for their stability and reliability.
In 1934, Switzerland passed laws, codifying centuries of customs about bank secrecy, and made it a criminal offense to reveal names of account holders to foreign governments. This was in response to German attempts to find where wealthy German Jews, who were being persecuted and plundered by the Nazis, were keeping their money.
Even before September 11, 2001, Swiss banks had become more selective about who could open, or continue to maintain, an account. This soon led to a ban on accounts for anyone sanctioned by the UN, or generally identified as a terrorist or very-bad-person. While the Swiss wanted the deposits (14 percent of their GDP comes from financial services), they didn't want bad publicity, or angry foreign government following through on threats to bar their citizens from dealing with Swiss banks.
There are actually plenty of other countries that provide discreet banking services, but the terrorists won't be able to avail themselves of such services in Switzerland.