Is it legal to hack a hacker back (in the US)?
<p>I was wondering if it's legal to do what most people call a &quot;hack back.&quot; Suppose someone tricked you into downloading software onto your computer that was designed to steal your data, but it was advertised as an online security software. Then you found out. Would it be legal to shut down their servers, or maybe even delete all the data on them, to prevent yourself and other people from this attacker?</p>
<p>Because I think of it sort of like self-defense: Someone tries to attack you, you can defend yourself (mostly). If a hacker attacks your computer, could you go and prevent them from doing so (by shutting down their servers)? I would think yes, but I don't have any idea of the law.</p>
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<p>I have taken a look at <a href="https://law.stackexchange.com/questions/57731/is-there-any-country-where-hacking-back-is-legal">this post</a>, and though it does clear a small bit up about this, it does not fully answer my question.</p>

<p>Generally, no.</p>
<p>The Computer Fraud and Abuse Act (CFAA), which is the law that generally forbids breaking into or damaging computer systems, does not have any exceptions for &quot;hacking back.&quot;  Congress has considered amending the law on multiple occasions (in <a href="https://www.cyberscoop.com/hack-back-bill-tom-graves-kyrsten-sineman-cfaa/" rel="noreferrer">2017</a> and <a href="https://www.lawfareblog.com/hackback-back-assessing-active-cyber-defense-certainty-act" rel="noreferrer">2019</a>) to add limited exceptions for so-called &quot;active cyber defense,&quot; but neither the <a href="https://www.govtrack.us/congress/bills/115/hr4036" rel="noreferrer">2017 version</a> nor the <a href="https://www.govtrack.us/congress/bills/116/hr3270" rel="noreferrer">2019 version</a> ever went anywhere.</p>

<p>Of course not. That would be equivalent to mugging a mugger back, or stealing from a thief.</p>
<p>Your one defence might be that you set booby-traps in your firewalls, which automatically slapped the hacker down.</p>
<p>Failing that, you would be committing a separate offence.</p>
<p>In true self defence and the heat of the moment, you'd be entitled to kill a mugger. Mugging the mugger back a day later would be a separate crime. You might be lucky enough to get your sentence reduced for provocation, but you'd still be clearly guilty.</p>
<p>Breaking into a thief's premises to &quot;steal&quot; back your own property might be justified but &quot;stealing back&quot; other things belonging to the thief, even things exactly matching the value of your property, should cut no mustard in any court.</p>

united-states hacking self-defense ethical-hacking justification