One, Khalid el Bakraoui, blew himself up at the airport, and the other two were arrested for planning attacks.
From the New Observer:
According to reports, the two men that came through Leros, Naim Al Hamed and Sofiane Ayari, used Syrian passports and were accomplices of Salah Abdeslam—in custody in Belgium for his role in the Paris attacks last November.
The third man, Khalid el Bakraoui, who blew himself up in the Brussels metro, had flown to Greece from Italy using Belgium travel documents in July but failed to raise suspicions of authorities in either country.
Ayari was arrested on March 18 along with Abdeslam in a counterterrorism raid in the Molenbeek suburb of Brussels while Al Hamed was involved in both attacks at Brussels metro and airport.
Greek police sources said that Ayari and Al Hamed had traveled by the infamous “refugee” ferry to Piraeus from Lesbos before moving on to Central and Western Europe.
I’m sure dozens of deaths and hundreds of horrific injuries are worth it as long as you get a couple dozen likes for turning your facebook profile pic to “Refugees welcome”