Not only will telecom and service providers turn over information to gov authorities with warrants, they will also turn it over to attorneys with approved legal demands and subpoenas for information in legal cases, divorce proceedings, etc. There is also difference between call detail records (numbers you call and who called you, plus duration of call) and call content (voice content with legal wiretap, and text msg content). It's very easy to get order of call detail records for voice and text messages, text message content requires additional effort but is easily available, while voice content required prior approval of a wire tap and can only be operated by law enforcement and only under the most strict and stringent monitoring rules for limited time periods.

Your biggest risk is records of your calls and text messages and text message content which are easily available with legal paper. Voice call content is very hard to obtain..

Yet, most folks these days avoid voice calls and prefer to use text messages, of which message times and content can easily (and legally) be obtained by either law enforcement or divorce attorneys. Go Figure?