I would also recommend that you don't trust binaries just because their source code is available. It is perfectly feasible to hide malicious code in plain sight or introduce something bad in the build process.
I don't, it's available so I read it. I provide comments on it. I participate in the community that is an open source project. Could you hide malicious code in plain sight? Sure. Would the project see the light of day when said malicious code was discovered by someone with knowledge and the time to read the code? Nope. I'll use an open source project over a closed source one in a heart beat for that reason. The likelihood something is hidden, and undiscovered, is much lower.
Bitcoins have helped expose how lax our security has been and if we want it to succeed, we have a lot of work ahead of us.
And how did Bitcoins expose lax security? Because users had trojans? Because a site got hacked? What does any of that have to do with Bitcoins? We don't need new banks because someone hacked a bank.