Remember the fear of Brexit and Trump disseminated by the elites?
In France they are going a level up with Le Pen (kind of justified as she will wreak havoc for real in their plans).
Seeing that accusing her of misappropriation of EU funds to pay for French party expenses did not work, they try another way.
They just took off her immunity so she can be prosecuted for posting two IS violence pics on twitter in 2015.
This could backfire as French people suddenly could understand who is really against the elites. Not Macron or Fillon.