[celticninja]

I imagine it's dependent on how the software is marketed. If you advertise it as a way to spy on others and steal passwords and banking logins, then it's pretty obvious it was built and sold with that intent. I imagine it becomes more grey if there are people who use it nefariously but you market it as a security analysts tool.

Also it seems like taking down the website stopped the software working. If it was centralised then there is a link between the theft of bank logins and the associated fraud directly to the website. Of course it might just be dialing in and checking the license as opposed to the website facilitating functionality.

Edit. Just seen an archived page for the tool, looks like a legitimate network access and monitoring tool. If that's the case then arresting the dev seems excessive. I did note that the page provided support, so I wonder if there was some entrapment along the lines of "how do I monitor for bank logins ?" Perhaps with enough info to make it clear the tool was being used to perform illegal activity, and that support is what fucked the dev?

[joe_the_user]

This.

A large portion of common law revolves around intent - I think the technical term is "mens rea" (mentioned by another poster).

If a site sold knives as "neighbor killers", with the comment "use this and you can definitely kill your neighbor, $19.95", then all the same considerations would come into play. And knives aren't illegal, at least to cook with.