Most foreign interference? BBC, Mexican billionaire who owns the NY Times, or 13 Facebook trolls?

I'd rank them like this from most (and worst) to least:

Carlos Slim/NY Times
BBC
Russian "interference"

The BBC is a multi-billion dollar state subsidized British operation with a rabid leftist, anti-American bias and they hate Trump even more than the US media does. But they have less impact on the daily US news cycle than the NY Times does. The Times' largest owner is now a Mexican billionaire who's one of the richest men in the world, personally accounting for an estimated 6% of Mexico's GDP. The paper has had a leftist bias for decades but under his influence it's become a true propaganda rag with no credibility or journalistic standards whatsoever, with a particular emphasis on promoting his open borders agenda and demonizing any American who opposes it. Millions of Americans' daily news consumption is shaped by the NY Times one way or another and leftists in particular often take their cues from it.

The 13 FB trolls had no impact on the 2016 election, let alone an ongoing impact on US politics. Unlike the two heavyweight, foreign owned media operations they didn't even monolithically favor either side, at one point simultaneously promoting pro Trump and anti Trump protests within blocks of each other.

In fact countless other forms of foreign interference in US elections would outrank the Russian FB trolls, from China's donations to Clinton in the 90s (which likely prompted him to lift export controls on dual use technology against military advice, resulting in China having advanced, accurate, dangerous missiles today) to disgraced British spy Steele and other foreign agents (from Russia and Australia) working with corrupt Obama DOJ officials to invent the Trump "dossier" and using dirty tricks to try and entrap members of the Trump campaign. But it's not like most of those crying loudest the past two years about "foreign interference" truly care about foreign interference. Many of the same people are fine with illegal aliens voting and don't even want us to have national borders.