I wonder about one thing possibly related to "wiretapping"... Consider a person, who has really bad memory and frequently forget things. He may consider puttin

I wonder about one thing possibly related to "wiretapping"... Consider a person, who has really bad memory and frequently forget things. He may consider putting some sort of device on himself, which would record everything happening around. Then, if something was forgotten, this person may use his records as a sort of "external memory". Would such kind of "memory aid" be legal? Edit: Also, if so — wouldn't (in a story linked) child's statement that she knew that the bear was a recording device legalize the situation? (Considering the bear wasn't left somewhere to record, but always remained with kid)