*dons 'trust me, I'm an IT professional and security certifier' hat*
A while ago, I was doing some research for the longboat model I got as a blogger Secret Santa, and found a link to a build on Model Ship World which included some very useful photos of a part I want to built using work's new 3D printer. So I bookmarked it.
Go on, click the link.
It turns out Model Ship World had a catastrophic hard drive failure shortly after migrating all the posts to their new forum system. Every single post from the old forum is gone: most of them might be on web.archive.org, but they're a complete sod to find because of the way phpBB handles its URLs, and I'm pretty sure the entry I want isn't.
The moral of this story, because, damnit, there are several, and I'm actually both quite cross and dead serious:
The Internet is not your memory.
There is absolutely no guarantee that todays useful link won't be tomorrow's "404: The requested URL /phpBB2/viewtopic.php was not found on this server." If you want to save a link for later for research purposes, use something like Evernote that will store you a copy of the content locally on your hard drive.
Back the heck up.
The above applies just as much to your blog, my blog, anything that's stored online/on the Cloud. Blogger has a backup facility - go to Settings/Other/Export Blog and grab a copy of the export of your blog contents every so often and save it someplace you can find it again. This won't save your images, but if you go to picasaweb.google.com, it should redirect you to a page where you can download the Picasa album that corresponds to your blog photos, if you haven't kept your own local copies.
Do it now. I'll wait while you do.
Why? Because Google have already proved that the thing they're really betting the farm on is Google+, and one day I will NOT be surprised to discover that my choices have become 'use Google+' or 'export your blog someplace else'. If you're not paying for a product (Blogger), remember, you are the product, and if we as users of a service stop being worth their while, they'll drop us. Same goes for Flickr (which Yahoo! seem bound and determined to screw up), Google Wave and heaven knows what else.
You're welcome to assume competence, good faith and lack of self-interest on the part of people providing an online service, but take backups anyway: an errant 747 hitting their data centre, or Amazon S2 having a major outage, is going to ruin their day however nice they are. And you don't know that they take proper backups, that they won't someday forget or fail to pay their hosting bill, or that they aren't one guy with one small Linux box in a cupboard at the end of an ADSL line (I should know. I am that guy, and I do take multiple backups and carry spares of most bits of hardware!).
Back the heck up 2.
Your hard drive. We live in a world where a scary amount of the information we create, be it text, photos, whatever, only exists in digital form. Look back at Model Ship World. The admin's defence was, to paraphrase: "we're not IT professionals, we didn't take backups, move on". I made a point of closing that window before I was tempted to register and comment (which would probably have resulted in my time as a registered user being one of the shortest on record).
This is 2013. There is absolutely NO excuse for not having a backup of the data you care about, doubly or triply so if it's not your bloomin' data. Hard drives fail. You do stupid things (I lost a massive pile of cherished RPG logs by accidentally having the wrong folder selected when I did my two sets of keystrokes for 'move to trash, empty trash' in too-quick succession).
Go to your favourite tech retailer and buy a USB hard drive - here, look, I'll even provide a link to a nice 500GB drive for under 40 quid! Label it prominently 'BACKUPS', don't use it for anything else, and use any of the scads of free backup solutions (some of which even come with your OS) to keep a safe copy of your data. If you want to use an online backup solution as well, that's fine - but don't make it your only one, for reasons stated above.
Oh, and every now and then, make sure you can recover something from the drive. If there's the merest hint of a problem due to the drive itself, buy a new one. There's a saying in IT: "No-one cares if you can back up. Only if you can recover."
Is your data worth more than £40 to you?