A former hotel employee said that employees might spoil guests' toothbrushes 
Former hotel employee Jacob Tomsky listed ways of revenge , which hotel staff use in relation to rude guests. The Sun writes about this.
So, the man said that problems with access to the room using a key card may indicate that the guest disrespectfully treated someone from the hotel staff or raised his voice. In addition, sometimes hotel employees can, in spite of rude guests, steal drinks from the minibar from their rooms or spoil their toothbrushes.
According to Tomsky, most often the victims of revenge are rich guests, because they treat the staff downright and do not consider them for people.
Earlier in December, former flight attendants revealed the most unpleasant aspects of their profession and dispelled the myth of “glamorous” work. For example, one of the flight attendants noted that during her work she had many times encountered the cleaning of excrement outside the toilet.