This week the Spanish police have arrested 10 Romanians who were responsible for conning around 300 people out of more than half a million euros in total. How? By renting holiday lets that don't exist around the Spanish islands including the Canary Islands of course.
The organisation first opened false bank accounts (this time in Valencia) then created various false web pages and finally worked via email to collect deposits/payments via bank transfer. As soon as they received payments they withdrew them from cash points leaving the accounts empty at all times. Often victims didn't realise they had been scammed until they arrived at the airport with nobody to collect them or to their accommodation to find it didn't exist or was somebody's home.
Whilst I'm not sure about the laws in the Balearic Islands, here in the Canary Islands it is illegal to rent a property privately unless you have a touristic license. If you want to rent a private villa or apartment via the Internet from someone you don't know then before you part with any money, ask them to send you a copy of their touristic license and have it checked out.
Whilst it is quite likely that the owner of a property in a residential town away from popular tourist resorts has such a license, properties advertised privately in resorts won't. A few of the destinations here on Gran Canaria where licenses are almost impossible to come by are Maspalomas, Playa del Ingles, Puerto Rico, Patalavaca, Mogan, Tauro, Taurito and Las Palmas city whilst rural properties around the island and the towns in the north are more likely legal destinations. Additionally, only accommodation on complexes where more than 50% of the properties are tourist rentals will be considered. Usually the agent renting out the apartments or bungalows will also be located on the property itself. Any exception to this rule (very few but they do exist though again, not in routist resorts) will have written permission from the local "Ayuntamiento" (council) allowing them to offer rentals once they have registered correctly for inspections and tax purposes. Again ask for a copy of that permission and have it checked out. That menas if you Google the property or complex you should find plenty of other known agencies offering rentals there along with plenty of reviews on pages such as Tripadvisor.
Be very, very careful before you transfer money to a private individuals bank account for a holiday rental. Try and use someone who uses paypal or another third-party payment system who offer you protection and a money-back guarantee if you don't receive what you've paid for.