How to check Syria's compliance? With citizen journalists

How can we be sure of what is happening in Syria after the ceasefire deadline? The absence of independent Syrian journalists and of international correspondents limits the capacity to report on the ground. The association Avaaz has been using a network of "citizen journalists" to get a better sense of how the ceasefire is respected or  not.
Read their story here:

https://en.avaaz.org/306/is-the-ceasefire-holding