[telltruth]

If employee is found using company resources inappropriately (in this case, mailing list to rant) then you can't give that employee 2 weeks notice. Google will then have to consider possibility that she will abuse their mailing lists.

[zomglings]

Google has internal mailing lists dedicated solely to rants (and related discussions) and others on which rants are certainly well accepted.

Google exercises a subjective standard to determine whether or not an employee is using mailing lists inappropriately (e.g. James Damore).

Source: ex-google