We see an example of this new found disrespect, with the BBC Technology commentator, Bill Thompson, in his latest output on the BBC News site, found here, titled, 'Can we stop the bloggers?'.
Thompson was invited to a closed-forum discussion that took place under the "Chatham House Rule", which reads:
"WHEN A MEETING, OR PART THEREOF, IS HELD UNDER THE CHATHAM HOUSE RULE, PARTICIPANTS ARE FREE TO USE THE INFORMATION RECEIVED, BUT NEITHER THE IDENTITY NOR THE AFFILIATION OF THE SPEAKER(S), NOR THAT OF ANY OTHER PARTICIPANT, MAY BE REVEALED"
Ironically Thompson was there representating the views of the blogging world and how it has transformed the world of publishing. While the meeting progressed, Thompson happily typed up his notes into his blog and thus null'n'voiding the very rules he was duty bound to uphold. Realizing his mistake, he owned up, and noted there was nothing more he could do because it was already published, the blogging engine took over, indexing and sharing his words throughout the world.
Thompson however was being a little naughty here, not owning up to the logistics of the Internet and believing that one can't control the flow of information. It takes a finite amount of time from when you publish your blog, to the time when people start reading it, and the various search engines and aggregators start indexing your content.
Thompson could have easily unpublished the item on his blog and minimised the exposure. The respected search engines, would quickly drop the entry from their indexes once they seen the "410 Permanently Removed" HTTP response from his blogging software. Aggregators also respect this basic HTTP error code that has existed since the world wide web first burst onto the scene.
The entry could have easily been removed from the majority of people seeing the words contained within. But Thompson used this an excuse to simply continue and let the entry exist; "publish and be damned". Respected journalists such as Thompson, while positioning himself as a blogging expert, can do the blogging world more harm than good by playing on peoples fears and myths about the Internet.

In an interesting twist of fate, at the time of writing this entry, Thompson's blog site was actually unavailable for public viewing, illustrating perfectly how easily it is to restrict access to your words.
Your blog is a valuable publishing tool, but remember it is a publishing tool, one can make corrections, additions, and removals at your will. You are your own editor, you have ultimate say on what goes on your blog site and assuming you have chosen your blog software properly, Pandora's box can indeed be closed again.
The largest barrier to "closing pandora's box" is probably the web cache.
You are absolutely right, the Google cache can indeed be a useful device
for finding a previous version or deleted entry. But they don't keep it
forever though; if the URL the cache is of, returns back a 'Permanently
Removed' status, then Google will remove it.