The very first sentence of the Kickstarter page says, "Space Monkey is the next generation cloud. For $10 per month, you get a full Terabyte (1000 Gigabytes) of storage you can use anywhere, any time."
Your argument is that the lease is implied, @emil10001's is that ownership is implied - I can read the page both ways.
The whole problem seems to stem from the lack of an explicit statement on this - perhaps it should have been in the FAQs?