What do these phrases mean and indicate?

In the context of SNS, media literacy has been argued to be especially important in order to make the users aware of their rights when using these tools, and also help them acquire or reinforce human rights values and develop the behaviour necessary to respect other people’s rights and freedoms. With regard to peer-to-peer risks such as bullying, this last element is of particular importance. This relates to a basic principle that children are taught in the offline world as well: ‘do not do to others what you would not want others to do to you’. This should also be a golden rule with regard to SNS, but for children and young people it is much more difficult to estimate the consequences and potential serious impact of their actions in this environment. Hence, raising awareness of children from a very early age about the particular characteristics of SNS and the potential long-term impact of a seemingly trivial act is crucial.

Hi teachers.

Most of all, I apologize for re-post. I didn't get the answer the other time and really want to know what these phrases indicate in the senteces.

The above is from the book I study.

First, I'm wondering what 'this last element' refers to in sentences. Also, I do not know what "these tools" refers to.

Always, thank you so much.