Tomas put it nicely, in the other thread:
You get out of it what you put in.
I know people who are using Flickr for a wide variety of different purposes and it's just as secure as any other image hosting site i.e. it's not. As long as you appreciate the risks involved with making images publicly available for download then there's no reason why Flickr should be any less secure than any other popular gallery of similar ilk.
There's a huge social element, if you're so inclined and I've made lots of real life contacts through Flickr who I now think of as friends.
Using Flickr can be a great way to get exposure. Most of my online image/print sales have involved Flickr in some way and I've been contacted by a number of organisations regarding the use of my work through it.
There are also plenty of opportunities to had too. Just off the top of my head, I can recall two competitions run through Flickr recently; one by the Anglican Cathedral and another by the Mersey Ferries company. Both involved worthwhile prizes and some form of recognition.
Almost a year ago, a group of local togs (pro and am) and avid Flickr users decided to form a collective. Months later, we held our first exhibition which brought in thousands of visitors. We now have a wide network of contacts in the media and are working with other organisations on projects. Oh, and we still post on Flickr and pat each other on the back.
If all you want is somewhere to share photos with friends and family then Flickr is great for that.
If you're wanting to look at and share images in niche interests then Flickr is great for that also.
If you want to reach out to newspapers and magazines then you can also do that through Flickr.
If you want to meet other togs in your local area and go on photo meets then sure, use Flickr.
I could go on, but hopefully, you get the idea.
