As was mentioned before, they are part of SBB’s Rail Fair campaign (violence and vandalism prevention probably

).
in german and
french
By showing their presence and by mediating conflicts, they provide a preemptive contribution to calm and order. With their professional approach to customers, prevention assistants bring back humanity to trains and put reckless behaviour in its place. When they have come by, your compartment will not feel as anonymous as before and the travellers will be less indifferent to each other. This surely makes a difference!...

They are members of the train police/Bahnpolizei, their only weapon is the phone.
Other roles in this Rail Fair campaign
are:
- Train station "godparents"/Paten who voluntarily provide customer support
- Grands frères/Grandes soeurs (young unemployed who do practically the same as those prevention assistants, max. for six months)
- Fan attendants (who travel with football/hockey fans in the Extrazüge)
- School children attendants
Never heard of this and the campaign started in 2003…Does someone know the number of people involved?