I am the founder and current CEO of a dedicated server host. The FBI and other law enforcement agencies do often contact us regarding activity emanating from or related to our network. Its the same for any host and the bigger you are, the more often it happens. Rarely, a local law enforcement officer from within or outside of the US get cranky when you tell ask them to get a subpoena (makes work for them). However, in my experience the FBI and other three letter agencies are very professional, fair, and genuinely want to do it right. Getting a subpoena is no big deal at all for them. Usually the US Attorney is right down the hall from them, in the same building.
They do officially have policies and programs designed to befriend local businesses in the area of a field office. They just want to catch the bad guys and not mess with the innocent. They want people to like them and trust them. They count on the cooperation of businesses, especially hosting and access providers. There are civilized processes for everyone to get what they want.
There are the cases of people trying to get information who are not actually law enforcement, and that is one of the many reasons you must ask for a subpoena... To protect yourself and your customers privacy. The FBI can get one in a very short time.
Where this all goes bad is when you do not respond to subpoenas for subscriber information, when you don't hand over the disks, etc. If you do not comply, then what alternative does the FBI have but to come and get it?
My guess?... The host didn't play nice with or respond promptly to the FBI.