Safety in Maspalomas is not particularly something to worry about. But travelers note that the dangerous area of Maspalomas is near the beach, where local analogs of gypsies roam. On the beach itself, they do not go in, but on the way they try to "fortune-telling" or remove watches and rings from your hand. So be vigilant!
Of course, you should adhere to elementary safety rules and not leave expensive things in a visible place in a hotel or restaurant.
In addition, beware of too bright sun (it is better to sunbathe in the morning) and large waves - even with the slightest excitement of the sea to swim in Maspalomas is not recommended, especially with small children.