3800 billion francs in assets managed by Swiss banks in total.

About 1.4 trillion francs in assets from foreign institutional investors, about 133 billion francs from foreign corporations, and about 670 billion Swiss francs (about $570 billion) (18% of total) on behalf of foreign private investors, according to Swiss National Bank data.

http://online.wsj.com/article/SB123638939161158787.html

USA Swiss cross border battle. US is trying to get the names of 52 000 wealthy US secret customers of UBS

UBS maintains that turning over the account names would violate Swiss privacy law and jeopardize UBS' license to stay in business.

UBS on Feb. 18, 2009 agreed to pay $780 million in fines and restitution for conspiring to help American citizens violate their country's tax laws by hiding assets-estimated to be worth at least $14.8 billion-from the U.S. government.
The bank says it has shut down the improper foreign-account business, and taken corrective measures to tighten its compliance and internal control systems.

Offshore tax abuse is estimated to cost the U.S. $100 billion a year in lost tax revenue.

http://cbs2.com/national/ubs.swiss.bank.2.950439.html
http://cbs2.com/national/UBS.AG.swiss.2.939843.html