Salami slicing is a pejorative term to describe engaging in a series of small illegal activities that, when added up, create a large impact and a potentially serious crime. In a simple example, a bank employee could always round down on transactions and pocket the difference. A few pennies here and there in small transactions is hard to spot, but the cumulative effect across numerous transactions could be significant. People also use this term outside the law, also in a negative sense, to describe situations where people try to get away with something by taking a series of small steps instead of one large and very obvious one.
For the person committing the crime, salami slicing can be a good strategy. It is harder to notice a cumulative crime than it is to identify one very large criminal act, and it may take time to realize what is going on. The salami slicing exploit is also used in computer hacking, to access a system by bits and pieces. If someone does start to notice, it can take time to identify the pattern, and it's possible some of the small actions will not be traceable, making it challenging to successfully prosecute the criminal.
The person engaging in salami slicing can keep an eye out for signs someone is aware of the activity, and may adjust the strategy or temporarily stop. This will lead people to relax their vigilance, thinking the problem is gone, allowing the criminal to start again. Over time, the losses as a result of the activity can be significant, including substantial funds, big data compromises, and other issues.
To prevent this type of fraud, people can use a number of techniques. Regularly scanning transactions and activities in a computer system can help people turn up irregularities or patterns of concern. Rotating employees and auditing to keep people constantly in motion can make it harder for someone to set up a salami slicing scheme. In computer security, an adaptive security system with multiple layers can identify intrusive attacks, even small ones, and address them to prevent a larger breach.
People may also talk about salami slicing in the sense of slowly chipping rights away or slowly changing the nature of a law. In regions where people have concerns about civil liberties and the rights of citizens, a small step to limit rights may be viewed with suspicion. People could fear that the one law will open the door to others, eventually eroding civil liberties and potentially having unintended consequences like limitations on free speech.