English to Chinese Tech/Engineering IT (Information Technology) Data breach

Be aware, also, that it is increasingly common for the government to request information about individuals from companies who have such information in their possession. Not every government request is valid, particularly if the request is not supported by a proper subpoena. Any request should be carefully vetted, ***as a phone companies very publicly learned when*** they cooperated with government requests for customer information in the post-9/11 period.
这句话有没有语病？没看明白是什么意思。