Facebook CEO Mark Zuckerberg has hit back at claims free services, such as his own social network, turn people from consumers into products.
Earlier this year, Apple CEO Tim Cook pointed to the habit certain unnamed free services have of collecting user data from emails, instant messages and web browsing behaviour in order to sell targeted advertising.
"Our business model is very straightforward: we sell great products," said Cook. "When an online service is free, you're not the customer. You're the product."
While Facebook wasn't referenced directly - indeed, it's thought Cook's statement may have been more of a snipe at Google than anyone else - Zuckerberg has seemingly taken it as a slight against his company.
"People increasingly seem to equate an advertising business model with somehow being out of alignment with your customers. I think it's the most ridiculous concept," Zuckerberg told Time magazine.
"What, you think because you're paying Apple that you're somehow in alignment with them? If you were in alignment with them, then they'd make their products a lot cheaper!" he added.
In many ways, it's not surprising Zuckerberg is smarting over Cook's remarks, even if it has taken nearly three months for him to respond.
In August 2013, researchers with security firm High Tech Bridge discovered Facebook automatically records links users send in private messages and, in January 2014, a class action lawsuit was filed in California, alleging the practice breached users' right to privacy.
More recently, it came in for criticism after working with researchers at Cornell University to attempt to manipulate users emotions, although what Facebook hoped to gain from the relationship is unclear.
This article originally appeared at pcpro.co.uk