From what I understand, bullying happens when someone is harmed through an online system that puts them in contact with other users, sometimes masking their identities.
Cyberbullying is defined in legal glossaries as
actions that use information and communication technologies to support deliberate, repeated, and hostile behavior by an individual or group, that is intended to harm another or others.
use of communication technologies for the intention of harming another person
use of Internet service and mobile technologies such as web pages and discussion groups as well as instant messaging or SMS text messaging with the intention of harming another person.
Examples of what constitutes cyberbullying include communications that seek to intimidate, control, manipulate, put down, falsely discredit, or humiliate the recipient. The actions are deliberate, repeated, and hostile behavior intended to harm another.
As such, could the "downvote" button, which is a major "feature" of the SE website, be considered a bullying tool?
It allows people to collectively, but in a hidden manner, criticise the work and input of a single user (instead of discussing with them to tell them they disagree).
This can in turn create a situations in which someone can feel like a group of people is against them, or voted down their content in order to harm them, or do not want to communicate their reasons to them (feeling of domination and exclusion can be reinforced if the person downvoted, as is often the case for a new user without "privileges").
The intent behind each downvote is not clear, and some users could downvote in order to harm if they wanted, this is a possibility and privilege given to them.
Or a user who believes they have been harmed by a down vote could claim the downvotes were made out of hatred since downvotes can be done without justification.
To summarise, could a bullying case involving a new user who got his question downvoted stand in court?
NOTE: I couldn't find "cyber-bullying" and "online-crime" or any related tags in there but feel free to add them if needed.