How is a person residing abroad subject to US law?
<p>I am reading <a href="https://www.justice.gov/usao-ndca/pr/three-individuals-charged-alleged-roles-twitter-hack" rel="nofollow noreferrer">this press release</a> of the U.S. Attorney’s Office for the Northern District of California.</p>
<p>The attorney states that:</p>
<blockquote>
<p>Mason Sheppard, aka “Chaewon,” 19, of Bognor Regis, in the United Kingdom, was charged in a criminal complaint in the Northern District of California with conspiracy to commit wire fraud, conspiracy to commit money laundering, and the intentional access of a protected computer.</p>
</blockquote>
<p>So the defendant appears to be located in the UK and is being charged in the US. As far as I know, UK people are bound by laws approved by the UK Parliament, and US people are bound by laws approved by the US Congress.</p>
<ol>
<li><p>How would the guy be held responsible under a law that the legislature of the country in which he resides did not approve?</p>
</li>
<li><p>What if he is convicted in a US court, the US sends a formal request to UK to have him sent in the US to go to US jail, and the UK government answers &quot;That's nice. We will not send him over&quot;? What would happen then? Would the US police fly to the UK and take him? Will the US nuke the UK?</p>
</li>
<li><p>What if the US asks for him to be punished in the UK, and the UK answers &quot;Sure. We will fine him 1$&quot;?</p>
</li>
</ol>

<p>The US has jurisdiction because the systems that the accused allegedly attacked are in the US.  To use an example with older technology, you can't escape criminal liability for defrauding someone in one country simply because you did so through the mail or by telephone from another country.</p>
<p>The UK and the US have an extradition treaty.  The UK might refuse to extradite the accused; in that case the US would most likely complain loudly.  If too many extradition requests are refused on one side, the other side might start limiting cooperation in any of several areas.</p>

<p>You do not have to reside in the US to be subject to US law (likewise UK law), nor do you even have to ever be physically present. <a href="https://www.justice.gov/usao-ndca/press-release/file/1300126/download" rel="noreferrer">The alleged crimes</a>,
18 USC 1030(a)(2)(C), 1343, 1349, 1956(h), only require involvement of US computers (which is the case) and not the presence of the accused in the US. At the level of international law, this is covered by Art 3 of the <a href="https://www.unodc.org/documents/treaties/UNTOC/Publications/TOC%20Convention/TOCebook-e.pdf" rel="noreferrer">UN   Convention against Transnational Organized Crime</a>, which both the US and the UK are parties to. This covers &quot;transnational crimes&quot;, and is applicable to cybercrimes.</p>

united-states criminal-law united-kingdom international extradition