Ethical Walls

In large companies, departments sometimes work on things that the colleagues next door must not know about. A bank might be secretly preparing a corporate acquisition while simultaneously recommending shares of that very company to its clients. If knowledge from one department leaked into the other, it would create an unfair advantage – and often a legal violation. Ethical Walls are the rules and barriers that prevent exactly that. The term literally means “ethical walls”: invisible walls between teams through which certain information may not pass. An older name for this, now considered unfortunate, is “Chinese Wall,” a reference to the Great Wall of China.

Why banks and law firms cannot operate without them

The most common use case is protection against insider trading. Insider knowledge is information about a company that the public does not yet have and that would move the stock price. Anyone who trades on it commits a criminal offense. An investment bank constantly holds such knowledge because it advises on corporate takeovers. Without strict separation from the departments that buy and sell shares, it would practically always be under suspicion.

A second case involves conflicts of interest. A large law firm might represent two companies that are suing each other. This is allowed, but only if the two teams work completely separately from one another. The same applies to auditors, management consultancies, and advertising agencies with competing clients. Here, the wall is the condition that makes the business permissible in the first place.

Regulators check whether such barriers really exist. In Germany, BaFin monitors banks on this point as well. Violations cost millions and permanently damage reputations. For many financial institutions, a functioning separation is therefore not a moral luxury but a matter of licensing.

What such a wall is made of

The technical part is the easiest to describe. File storage systems, email distribution lists, and databases are set up so that only a defined group of people has access. Anyone not on the list doesn’t even see the project – it simply doesn’t appear in their search. Such restrictions are called access controls and are built into almost every piece of enterprise software today.

Then there is the organizational part. Sensitive teams often sit on separate floors with their own key cards. Projects are given code names so that even a calendar entry gives nothing away. Employees sign confidentiality agreements and may only trade shares after clearance. A dedicated department, Compliance, keeps lists of who knows which secret.

A common misconception is that an Ethical Wall is the same as a firewall. A firewall protects a company from outside attackers. An Ethical Wall runs internally and separates colleagues from one another who see each other in the cafeteria every day. That is precisely why its effectiveness depends heavily on human behavior and not just on technology.

The problem with AI assistants in companies

In the news, the term currently comes up mainly in connection with AI. Companies are introducing assistant systems that answer questions about internal documents. Such systems work by making as many files as possible searchable. This stands in direct contradiction to a wall that deliberately keeps documents invisible.

The danger is concrete. A language model trained or fed with all company data could inadvertently reveal to a stock trader what the acquisitions department is working on. Providers are responding with access rights that are passed all the way through to the individual answer. The system is meant to be allowed to use only sources that the employee asking the question could open anyway.

For students and private individuals, the term usually remains abstract. One encounters it in reports about bank scandals or in job postings for compliance positions. Anyone who later works at a bank, law firm, or consultancy quickly encounters it in practice: as training on the first day of work and as a folder that simply won’t open.