The discussion of reasonable expectation of privacy in R. v. M. (A.) is extremely useful. In the wake of Tessling," many courts had effectively reduced the protection offered by s. 8 based on two arguments: that what was detected was an emanation in the public domain similar to heat coming from a house, and that what was discovered merely related to informational privacy and was not part of the biographical core of such data. Justice Binnie's decision puts paid the notion that either of these arguments is a trump card. He suggests that generalizing about "emanations" is not a useful approach, and that the nature of the particular technology used and its interference with liberty must be engaged in each time. With regard to informational privacy, he unambiguously reaffirms what had frequently been missed in Tessling, that the protection extends at least to the biographical core of personal information, but is not limited to that and extends further.