Thanks for your thoughts. I have warm fuzzy feelings about BitTorrent as a company, but if we have learned anything from the revelations about NSA and related agency activity, it is that companies can be coerced into violating the privacy of their customers whether they want to or not, while the legality of the action seems to be an almost irrelevant concern to the government agencies. This makes me sad but it is a hard truth that must be confronted in the absence of institutional reform. Is it possible in Linux for a process running as a normal user to access the memory of any other process run by the same user? If so, perhaps it is best to run Sync as a separate user dedicated only to that application. Would that be safe enough? What used to be paranoid behavior, as you say, now seems to be simply prudent.