A very complex domain
"If they give away something for free and they don't pay royalties, they ruin the economics of the business," Roger Kay, an analyst at Endpoint Technologies Associates, said of Google. "They've been doing that in industry over industry."
Just as Apple sued HTC rather than Google, Microsoft has taken aim at Motorola because the cellphone maker derives revenue directly from selling Android-powered phones, making it easier to make a case for financial damages.
Microsoft's suit carries risks because it needs support from handset makers to be successful. But among the companies it has worked with in the past in the mobile business, Motorola is the biggest that hasn't signed on to use Windows Phone 7 in its products.