There is no cap on FiOS data usage, as far as I know.
I have FiOS as well.
So it doesn't really matter.
OK, there is, kinda. But it is a soft cap, and it is WAY more than you'll ever see.
77TB in a month
http://arstechnica.com/information-technology/2013/05/fios-customer-discovers-the-limits-of-unlimited-data-77-tb-in-month/
"An IT professional who manages a test lab for an Internet storage company, houkouonchi has been providing friends and family a personal VPN, video streaming, and peer-to-peer file service—running a rack of seven servers with 209TB of raw storage in his house."