You're thinking about this I reckon: https://media.ccc.de/browse/congress/2014/31c3_-_6258_-_en_-_saal_1_-_201412282030_-_reconstructing_narratives_-_jacob_-_laura_poitras/download.html
He does say that there have been SSH sessions cracked, but that doesn't mean SSH in itself is insecure every time you use it. It still could've been mitm, or just insecure settings (SSH has different protocol versions, many different ciphers that can be used etc. of course some of them aren't secure). I think you can use SSH in a secure way, but you have to make sure you're using the latest version on both of your machines and that you configure it in a secure fashion, for example this guide seems to give reasonable advice from what I can tell: https://stribika.github.io/2015/01/04/secure-secure-shell.html
