The only true way to prevent these acts is to eliminate ideological conflicts altogether. Usually, this is done by letting the state pick a winning ideology and suppress those who don&#x27;t adhere to it. This tends to ensure a level of homogeneity that makes violence obsolete.<p>A more moderate solution is to allow conflicting ideologies to exist as long as they don&#x27;t reach extremes. This is usually done through mass surveillance, which supposedly should be able to catch extremists before they act. Sadly, we&#x27;re still very far from Minority Report&#x27;s level of accuracy.<p>Alternatively, we could adopt a more reactive approach which would focus on reducing the gravity of such events rather than trying to prevent them. Namely, law abiding citizens should be able to conceal-carry weapons. Although it couldn&#x27;t stop all kinds of terrorist attacks, it could very well put a stop to most mass shootings. This assumes an important &quot;good&quot; to &quot;bad&quot; people ratio (where &quot;good&quot; is defined by the majority and&#x2F;or by the state).<p>Basically, live in a society that&#x27;s xenophobic and armed.