Google translate is very poor for Irish and since only ~250,000 in the world speak/read it well enough to translate and 90% of those people are on an island it works quite well.
"the process of encoding messages or information in such a way that only authorized parties can read it."
It may not be a secure form of encryption, but it is a form of encryption.
It would be pretty effective against the random passer by, and standard law enforcement would probably not be able to identify the language.
Plus, virtually any encryption a user has can be broken given time and processing power. By hand writing everything in another obscure language, without many native speakers you gain plausible deniability. If he/she manages to get on a list, he/she could claim issues with translation (either by him/her or by the translator).
[1] NEWS: http://www.tg4.ie/
[2] Rosetta Stone: http://www.rosettastone.com/learn-irish
[3] Folclóir Póca (pocket dictionary)
[4] Learning Irish by Mícheál ó Siadhail
Now they also have it on Duolingo