DealBook is reporting that Yahoo is warning Facebook about a potential patent fight between the two Internet companies. Yahoo is asking that Facebook pay a licensing fee for a number of their patents, in the range of 10 to 20. Both Yahoo and Facebook confirmed this with DealBook in statements. Of course, it is normal for a company in decline to begin to seek out additional sources of revenue, and many companies choose patents. It seems Yahoo is going down that road.

[Source: DealBook]