In order to protect against fraud, there is a nominal maximum (unachievable in the legal use) for the total number of requests from the user's devices during a period of the service usage.

For a private person this is  (a number of months) x 1000 + (a number of additional devices) x (a number of months) x 100. 

For an organization this is  (a number of months) x (a number of devices) x 1000.