Valuable art should have adequate security. If the owner took the time to consider the possibility of someone stealing the artwork and preparing for a worse case scenario it could prevent the art from ever being stolen. If its priceless then it should be treated that way. Security measures such a good alarm system could keep the art from being stolen and help catch a thief before they get away with the artwork.
Yes, I feel this art piece should have had better security because of its value. When you take into account the percentage of the value that was spent on security it is next to nothing. Had they invested more into the security this piece would either not have been stolen, or would be found much quicker and returned to its rightful location.
Be it female Bansky or any other piece of art that expresses not only the thought and experiences of the artists but also depicts real life mysteries and situations need to be kept in the highest security possible.
Artist spends their lifetime trying to build a masterpiece like female Bansky and some anonymous immature person steels it because of lack of security, This is pure failure of system and needs to be dealth with.
The artists who endeavor to create street art are making a statement by creating their art in a public place. The inherent danger of a dishonest person stealing the piece is part of what makes the piece intriguing. It would change the whole concept and feel of street art if we had armed guards stationed around the work.