Many software packages come with a EULA which uses claims such as "by opening this package you hereby agree to ... (some laws going far beyond classical copyright)".
Now, what happens if your friend opens the package and installs it on his computer, and I would use the software not in a way permitted by the EULA.
For example, I decompile someone's code which they prohibit by EULA.
Under what grounds can I be sued? I never agreed to the EULA so it's not contract violation.