What can be designed to create annoying glitches or destroy data

Virus can be created to create disturbing problems or destroy data.

Explanation:

Virus is a mischievous program that self-repeates by copying itself to another program.  The virus increases by itself into other executable code or documents. It is really easy and simple for the viruses to slip into a computer by escaping the defense systems.So the virus is the reason to create the problems and for destroying the data. Virus enters its virus code to multiply itself by changing the programs and applications.  

Wifi router/

All links together are together