Because it's closed source, we don't /know/ how secure btsync is. However, we do know that microsoft, google and dropbox will just hand your shit over if the US government asks.
Something is better than nothing. The only open source competitors in this space are owncloud, who /still/ won't let me upload to both a work and person cloud at the same time, and syncthing, which I have high hopes for but which currently has a workflow so bad I think I'd rather just use a thumb drive.
I've stuck with btsync 1.3.94, the version with the beautiful workflow, just before it went off the rails. It solves my need to avoid google/facebook etc. /Maybe/ it doesn't protect me from the US government, but that's still better than dropbox.
I think bleep's gonna struggle, because it requires me to get /other/ people to buy into my disquiet, which turns out to be really hard if my experiments with XMPP over skype tell me anything.
You know what I might actually pay for? A gateway to facebook/gtalk/skype. I'd be willing to pay $5 per month for a bleep-to-everything gateway, either from bittorrent or someone else. Half of bleeps value is simply in my not needing another account (e: I could say the same about btsync).