The Sharebooster logo is actually stock art: https://twitter.com/#!/launchbit/status/163328570364669952

And it's a pure coincidence that a company called "curebit" chooses the exact same logo stock-art as one called "launchbit"

Well there's an interesting debate, there.

Launchbit bought a stock image. So even if Curebit saw the logo through Launchbit, is there a reason why they can't buy it too? I imagine the creator of the stock image wouldn't mind the extra money.

I think that using a stock image for your logo is probably unwise for exactly this reason.

Not only unwise, but prohibited: http://www.istockphoto.com/license.php

the kinoma link is much more of the accepted face of imitation, it just rubs a little after the previous issues.