Which of the following techniques can be used to access data not normally allowed by a system?

The choice of query tools pertains to structured ways of accessing and retrieving data from databases or systems, typically using languages such as SQL. These tools can sometimes be leveraged in inappropriate ways to access data beyond the usual permissions if the system is not properly secured. This unauthorized access could result from poorly designed database queries that do not enforce restrictions strict enough to prevent access to sensitive data.

While the other options have their specific uses, they do not align directly with engaging with data in the same manner as query tools. Data mining involves analyzing large datasets to identify patterns and trends, which doesn't specifically target unauthorized data access. Data scraping involves extracting data from websites or applications but usually does not involve querying systems that have permission restrictions. Script injection refers to inserting malicious code into scripts or applications, potentially gaining unauthorized access; however, it is a more aggressive and less controlled method compared to the more structured and legitimate approach of using query tools. Thus, query tools stand out as a method that can be utilized to access data not normally allowed, given the right structural vulnerabilities or misconfigurations within a system.