Apple is attempting to take control of the word 'pod' within product names.
The company is arguing that other companies that use the word within the names of their products are infringing Apple's iPod trademark.
Apple legal has been contacting companies that use the word within their products to demand that they change the name, threatening trademark violation.
The Financial Times reports that one Dave Ellison of Mach5Products, manufacturers of the Profit Pod, received a "cease and desist" letter from Apple "just after receiving trademark recognition for his product name in the US".
The iPod has spawned a selection of 'pod'-labelled products and words, including podcast, and podcast distributor PodShow.
In recent months, Apple has also been pursuing companies that use the word 'iPod' within their product or website names.
That pursuit led multiple online MP3 player accessory retailers to change the names of their stores.