encryption technology developed or at least modified by supporters of al qaeda. experts say it helps terrorists communicate in secret. and there s a mobile version of it. i isis has developed a mobile app that provides updates to news and propaganda with videos. and jihadi websites public tutorials telling militants how to hide tracks online and which apps to use for most secrecy. that provided pretty sophisticated guidelines what to use, what to talk about, how not to get their communications intercepted. reporter: text encryption techniques are right out of the show homeland. matthew green showed us one way terrorist ks make their texts disappear on the telegram app. you can program them to self-destruct in a few seconds. i send green a text to meet me somewhere. he reads it, then and just like that you ve got no record of the communication.
that doesn t mean we re safe. those are two different things. obviously we know terrorist ks get into our country. we ve seen it happen. i think in terms of they are obviously they obviously have the migrant crisis right in front of them. it s not something that s literally crushing against us the way it is against them. one thing i would say on that is that the manhattan institute has a study out about how in the united states, something that most of us think already, muslim immigrants tend to assimilate much better than they do in europe. that is also part of the problem in europe, which is that they are not assimilating. the muslim migrants are not assimilating. that brings us to the next topic. the debate over how to confront isis quickly morphed into a fierce debate over how to handle the syrian refugees and president obama seemed almost eager to call out republicans. take a look. these are the same folks oftentimes who suggest that