Is Microsoft getting paid for patents in Linux?

kripkenstein writes: "In an interview, Jeremy Allison (of the Samba project) implies that Microsoft is secretly getting paid for patent licenses on Linux-related products:

[Interviewer:] One of the persistent rumors that's going around is that certain large IT customers have already been paying Microsoft for patent licensing to cover their use of Linux, Samba and other free software projects.[...]

Allison: Yes, that's true, actually. I mean I have had people come up to me and essentially off the record admit that they had been threatened by Microsoft and had got patent cross license and had essentially taken out a license for Microsoft patents on the free software that they were using [...] But they're not telling anyone about it. They're completely doing it off the record.

If true, is this slowing down Linux adoption? Or are these just rumors — which may accomplish much the same effect?"