austria
What law were these counter-protestors in Vienna charged under?
<p>According to <a href="http://www.jpost.com/International/Vienna-police-charge-3-men-for-waving-Israeli-flag-at-rally-533313" rel="nofollow noreferrer">Vienna Police Charge 3 Men For Waving Israeli Flag at Rally</a>, which cites a German-language article in Vice magazine, three people were charged for pro-Israel counter-protesting at a "Pro-Palestinian" rally.</p>

<p>What law were they charged under, and has its validity been challenged either for its constitutionality or under human rights protections given by the European Union?</p>

<p><a href="https://www.vice.com/de_at/article/mbpp38/fur-das-zeigen-einer-israel-flagge-bekamen-drei-wiener-nun-post-von-der-polizei" rel="nofollow noreferrer">This is the cited article</a>. Thankfully, the interviewee provided a scan of the police letter he received, so the rest of this question is relatively easy to answer.</p>

<p>He was specifically charged with <em>Störung der öffentlichen Ordnung</em> (lit. Disturbance of the public order) persuant to <a href="https://www.jusline.at/gesetz/spg/paragraf/81" rel="nofollow noreferrer">&sect;&nbsp;81(1) of the <em>Sicherheitspolizeigesetz</em></a>, which reads (after putting it through Google Translate):</p>

<blockquote>
  <p>Who by a behavior that is likely to arouse legitimate annoyance, disturbs public order, commits an administrative offense and is punishable by a fine of up to 500 euros, unless the behavior is justified, in particular by the use of a constitutionally guaranteed right , In the event of aggravating circumstances, instead of a fine, imprisonment can be imprisoned for up to one week, or up to two weeks for repeated offenses.</p>
</blockquote>

<p>This law is almost certainly constitutional as it specifically allows exercise of constitutional rights. Note this also includes human rights, as Austria has <a href="https://de.wikipedia.org/wiki/Bundesverfassung_(%C3%96sterreich)#Europ%C3%A4ische_Menschenrechtskonvention_1958" rel="nofollow noreferrer">included</a> the European Convention on Human Rights as part of its constitution.</p>

<p>Given that, I'm guessing if the interviewee had wanted to, he would have had a decent shot at having this charge dismissed.</p>
