Most seasoned travelers probably know much of this already, but for the benefit of newbies who are seeking vacation apartment rental advice there is an interesting article at http://tinyurl.com/mrd6jz
Though the article headlines mention Paris, I have seen far more scammer ads for London. As mentioned in the article, a tip off is the request to send funds via Western Union.

How scary for an owner as well, to see you can have your own website or advertisement copied and pasted to make a scam!:-S

I think it would be foolish to send money or rent a vacation apt from any private owner just from a random ad on Craigslist or places like that. Craigslist is used for all kinds of crimes as it is free, as I understand it (to advertise) and the owners basically let anyone print anything with no concern. I'm sure you could also have scams on more well-known websites that private owners can use (eg, VRBO), but at least there is a bit more oversight there and it costs the advertiser more. I won't rent apts from unknown private owners not affiliated with a reputable agency that is registered with the govt, but I know lots of people will.

for those interested in renting in the UK, [outside London, I can't speak for the capital] you should look for owners who are rated by the local tourist board, who will provide you with a list.

to get on that list, you have to be vetted in person every year and attain basic standards including for fire and other safety features. you are then ranked according to the facilties you offer.

so you can book knowing that the accommodation does exist and that someone has inspected it in the last 12 months.

regards, ann

I feel the same way about renting a place because some anonymous poster on here said so, too.

perhaps paradoxically, I have rented via craigslist and will likely do so again. Never been burned, but I usually follow the premise that if it sounds too good to be true it probably is. Huge red flags are requests for western Union payment and offers of free airport pick up.