'Senior counter-terrorism officers have revealed that UK authorities are allowing potential terrorists to leave the UK freely, if it is calculated that the Islamists are more dangerous left in this country.'
Tuesday, 15 December 2015
Revealed: Potential Terrorists Are Being ALLOWED To Leave The UK
More here http://www.breitbart.com/london/2015/12/15/revealed-potential-terrorists-allowed-leave-uk/
This is absolutely the correct option with one proviso, that once they've left the UK they aren't allowed back. If they're more dangerous left in this country, then how much more dangerous would they be once they've received terrorist training?