They are easy to spot because they uncritically retweet utter rubbish published by pro-EU organisations, or ask innocuous but evidently ridiculous questions, inviting you to come back with a reply. They think they are laying a cunning trap for you to walk into. However, constrained by their own narrow thinking and ignorance, they don't think there is any argument you can possibly make that undermines their article of faith.
Here's an example of one such encounter today and the arguments I used to dispense with the Europhile's claim that the EU is democratic. Hope it helps.
If you don't already, do please consider adding me on Twitter https://twitter.com/MrBrexit and joining in the online effort to expose inaccurate and untrue Europhile claims.
UPDATE: The Europhile chap has come back with a response to my tweets... as you can see, like all Europhiles, they are impervious to facts and reality and persist with their self delusion.