It is a common practice in academic philosophy to use thought experiments to buttress arguments. The idea is that by designing and then imagining a case with relevance to the the specific aspect of the problem at hand, clear lines of distinction can be drawn, which can then articulate the reasons which motivate one solution rather than another. These thought experiments often, particularly in moral philosophy, involve people doing one thing or another, and, in order to distinguish between the various actors, names are required. For some reason, these names are almost invariably generic or at least could not be used to identify any private individual: A and B or John and Jane are perhaps typical. I have even heard people talking about whether they ought to have gender balance in the names of the fictional actors in their entirely imaginary thought experiments. There are a set of ethical norms governing the use of names, of public identification, in thought experiments.
The American leftish blogosphere has got into a debate about what might constitute a fair division of household labour, started by Matthew Yglesias making what I take to be a rather banal series of quasi-feminist points about gender roles and their effects on the division of household labour, and getting comments which ascribed gender roles to some form of morally legitimating choice. A lot of the debate since then has focused on the problem of free-riding, of misrepresenting preferences so as to exploit the greater willingness of others to complete some task, in particular the phenomenon of men being trained to expect that women will tidy up for them. Free-riding, conscious or otherwise, is undoubtedly a problem, simply because most people are both lazy and like tidiness. Notice though, that free-riding, as a moral critique, depends on the thought that it is exploitative to allow someone else to bear the burdens of keeping a space clean. If someone else is more willing than I am to use their time to keep a space we share clean, why should I waste my time, which I'd rather spend some other way, helping them? Why should I be making a sacrifice so as to allow them to be happy in that space? Why should I be concerned about how they feel about a space which we share, about the norms which govern the use of common assets?
In the 1992 US Supreme Court case R.A.V. vs. St Paul, Antonin Scalia wrote a majority opinion overturning a St. Paul Bias-Motivated Crime Ordinance on the grounds that although prohibiting what are in US jurisprudence known as 'fighting words' is constitutionally acceptable, attaching extra penalties to sub-categories of fighting words which are based on the meaning of those words is unacceptable. Judith Butler said of the Supreme Court's ruling
The burning of the cross which is, after all, on the black family's lawn, is thus made strictly analogous--and morally equivalent--to an individual speaking in public on whether or not there ought to be a fifty-cent tax on gasoline...the historical correlation between cross-burning and marking a community, a family, or an individual for further violence is also ignored...
Incitement to violence is currently a criminal offence, and rightly so, in British law. As of last night, glorification of terrorism, as long as the act of terrorism in question took place less than twenty years ago, will soon also become a criminal offence in British law. Thus, praise for the IRA's attempt to assassinate Margaret Thatcher in 1984 will not be criminalised, whilst praise for its campaign of bombings following the resumption of armed activities after the collapse of first ceasefire in the early nineties will be. It is unclear why murdering stockbrokers is worse than trying to eliminate an entire democratically elected government. The bombing of civilians by states, rather than other armed groups, seems to have escaped the remit of the bill totally. It is unclear why the use of violence in the pursuit of one political project is acceptable when it is not in the pursuit of another. Finally, it is unclear why, when there is a long tradition of art which undeniably glorifies political violence by non-state actors (via), actors who have killed thousands and militarised significantly-sized areas of the state during their campaign, this suddenly became so vital.
Public spaces can take a variety of forms. The living room of my shared house is a public space, at least for the public of those who live in my shared house. The fora in which political debate in Britain takes place are public spaces, or at least, collectively a public space. Both of them require, in order to respect the interests that all of members of the respective publics have in the structure and content of those spaces, that there are rules, a category which obviously includes both legally enforceable commands and simple norms of behaviour, which govern the structure and content of the spaces in question. To single out particular groups for discrimination, to ignore the ways in which the rules can make the burdens of entry and occupation excessively high, can prevent those ought to be members having the right to have their interests considered, is wrong in both cases. To do so is to effectively deny that those discriminated against are members of the public in question, to create a sphere of publicly-displayed privacy that they alone occupy where their opinion is diminished, explained away, made inconsequential. Sometimes it is possible to trace that privacy back to those who created it, to expose the technologies they manufactured it with, and sometimes not. We return to the thought experiments.
Update: it would appear that the time limit on which acts of terrorism it is legally permissible to glorify was eliminated during the course of removing a series of Lords amendments. So, as Nosemonkey points out, subscribing to a Whiggish theory of British constitutional history would appear to be in principle punishable by a spell at her majesty's pleasure.