In general, Google has not aggressively patented things. They have been issued ~300 patents. Compare to IBM's over 26k patents in the US alone. Is it possible

In general, Google has not aggressively patented things. They have been issued ~300 patents. Compare to IBM's over 26k patents in the US alone. Is it possible that Google's patent assignment policy has affected those numbers "in Google's favor"? [1] For example, could the policy be that patents are assigned to employees, but employees grant Google a non-revocable perpetual license to use those patents? (IANAL, etc...) [1] i.e. Fewer patents assigned to Google = less aggressively patenting.