I totally agree about PayPal, though if you paid someone by cheque then they'd see your bank details; sort code, account number and account name. I don't believe anyone can do anything with just those. I've sold a lot of things on Bumtree, including some quite expensive items, and always advertise cash on collection only. I always make sure I'm not at home on my own when they call, I never let them see anything else that I may have; MacBook etc, whatever I'm selling is set up downstairs. You just have to be careful. On the whole everyone I've encountered through there has been fine, though I did almost fall for a scam a few months ago when I was selling a pair of Genelec monitors, I posted on here about it at the time. At the end of the day, if you're unsure then just walk away, someone else will no doubt be interested.