Reds in our beds

Mr Putin likes to have influence in the EU. That is hardly surprising as the EU is a very large, very successful, very powerful neighbour. Look at the problems caused in Mexico by that sort of situation.

The problem is that Mr Putin prefers to use propaganda rather than diplomacy, and his background in the KGB means that he is very good at propaganda. Not just the content but also the channels he uses.

The Russian media outlets RT and Sputnik are well known for their biased news coverage, and even fake news reports. However, not many British people watch these channels. Of far more concern is the admissions by Google that in recent EU votes they sold Mr Putin's minions advertising slots, slots for ads persuading people to vote for Brexit.

Equally concerning is the number of Twitter accounts that the Russian state controls, many being run from a 'troll factory' in St Petersburg. 150,000 Russian Twitter accounts switched to focusing on Brexit in the run up to the referendum and posted around 45,000 messages about Brexit in the two days before it. After the vote they simply switched back to their pro-Putin posts.

Facebook accounts were also involved, but it is impossible to discover how many. Facebook has refused to help investigate how its platform was used by the Kremlin, even though Facebook-based propaganda is more influential than Twitter feeds. Facebook's boss, Mr Zuckerberg, stated it was a "pretty crazy idea" that Facebook posts could influence votes - despite raking in $10 billion in advertising revenues. Clearly advertisers think it can influence people even if he doesn't.

Meanwhile the Legatum Institute is also being investigated for long-term Russian influence. The institute is an outspoken advocate for Brexit and has very close links with Conservative Brexiteers - for example, Mr Gove and Mr Johnson's recent letter to Mrs May voicing concerns about her approach to Brexit was adapted from a paper produced by the institute.

Of course, it may be that Mr Putin has simply been giving some moral and financial support to his admirer Mr Farage and has no wish to see a fractured and weakened Europe.

None of this invalidates a single vote in the referendum. People voted freely, and we can't say whether any were influenced by the propaganda. The point of the investigations is to find out exactly what is happening, and prevent future elections being subverted by foreign powers. You could say it is "taking back control".