Yes (though I do have to tread carefully here).
Done right I support the idea of getting access to the correspondence of individuals - however so far I disagree with pretty much every practical implementation.
Interception leaves a particularly bad taste for me. I've seen it done once; as it happens for the right reasons and with a positive result. It still left me feeling a bit crap because of how it was done (with only the vague vestiges of a warrant).
On the other hand I would have no compunction about breaking into the email account of an individual if the need arose (i.e. requiring correspondence to prove or stop a crime).Ironically doing so is a) technically reasonably easy (especially if you have their computer) and b) legally next to impossible to do - usually you have to use RIPA and go to the ISP... (aka months, though I dont deal with that area of stuff so Im not sure). So it's where you draw the line morally and ethically.
Intercepting every mail is clearly a massive infringement of our privacy rights. Intercepting an individuals correspondence where there is a serious degree (not just a reasonable one) of suspicion to warrant the action I can agree with - but as yet there appears no realistic mechanism to do this without creating an easily subverted system which can be used wrongly.