PageRank patent and Yahoo, MSN, etc.

can't google stop others?

[flex55]

As I understand Google has a patent over the PageRank concept, and over the concept of "ranking your site based on inbound links".
As we know, Yahoo and MSN also use this factor to rank sites.
Can't Google just sue them for breaking a patent?

[Brett_Tabke]

No - there are many patents related to search technology.

We do not know that Yahoo or msn use anything related to pagerank.

We do know, that Yahoo holds a ton of patents related to search they acquired from Altavista. Some of those patents may actually superceed the PageRank Patent.