@nekoinemo
Skype is probably the worst big chat service. Microsoft is granting the NSA and other US agencies full access to it¹. The texts are not properly end to end encrypted and Microsoft reads them² also the voice chats are auto transcribed and scanned for keywords³.

And from what I hear from the users, the software doesn't even work properly most of the time.

1) https://arstechnica.com/tech-policy/2014/12/newly-published-nsa-documents-show-agency-could-grab-all-skype-traffic/

2) https://arstechnica.com/information-technology/2013/05/think-your-skype-messages-get-end-to-end-encryption-think-again/

3) https://theintercept.com/2015/05/05/nsa-speech-recognition-snowden-searchable-text/