Arriving in Morocco, at the big stations or all the places where tourists are you will find sometimes bad people ...
But this is everywhere in the world. So never get paniced.
Do your own thing. If you do not want to get into contact with such strange persons, do not react on their questions, do not look in their eyes, just ignore them. If you look in their eyes, you are allready involved in a discussion.
To be realy safe, select your hostel in which you want to stay already from Europe or read in a Lonely Planet book which ones are good at the moment.
When you are in the hostel, you can ask there for a serious city guide or ask them to call you a taxi. Do not ask a bad person which you meet at the station or on the street to show you the city.
You won't be killed, but it laready happened, that the bad cityguide goes with you deeper and deeper in the city and then in a little store you have to buy for all your money only trash things with no need.
When you go on the country side, people are less dangerous.
So do not forgett, Morocco is Africa, the culture is different from Europe. There are a lot of very very nice persons, but also some which are bad. Open your eyes and nothing will happen.
For the start when you come over by ferry to Morocco, it is good to ask some other travelleres on the ferry to join in the taxi to the hostel. if you are a group, it is realy safe.