I wouldn't do a "my sex with Jedward hell" style kiss-and-tell to the papers. (Look, it's Jedward!)
If I have a long and interesting prossie career, I'd consider doing a book though.
I agree - if you have something genuinely interesting to say about the world, a book is good! But going to the spawn-of-satan tabloids to sell a tedious "scandal" story that just makes you look like an idiot? Er, no thanks. In my perfect, imaginary version of the world, tabloids & crappy media in general just wouldn't exist, so the likelihood of me selling a story that, at the end of the day, some rich tabloid-owning media mogul would profit off far more than I ever would just goes against my very nature. *grumbles*
Er, and yes, I take discretion seriously and even in a book would never mention a client's name! No point - again, it'd just make you look bad (and get sued, possibly!). So making ?20k (if anyone would even pay that much these days?) would be nothing compared to what you'd lose in the long term.
I've never understood the desire to be "famous" (aka bitched about by thousands of people you've never even met) so I don't think I'll ever understand reality TV, tabloids or Jeremy Kyle.