I guess you're used to standard billions (a million millions). A US billion would certainly suffer from losing hundreds of millions, you're talking about a double-digit percent.
I doubt they are saying any services out there have 1,000,000,000,000 users.
10^9 is the standard definition of a billion, it's very wrong to call 10^12 a "standard billion." You can say "long scale billion" if you want to refer to the definitively non-standard 10^12 billion.