taint()
public
Mark the object as tainted.
Objects that are marked as tainted will be restricted from various built-in methods. This is to prevent insecure data, such as command-line arguments or strings read from Kernel#gets, from inadvertently compromising the user’s system.
To check whether an object is tainted, use #tainted?.
You should only untaint a tainted object if your code has inspected it and determined that it is safe. To do so use #untaint.