More about what you can say. The British Humanist Association was not allowed by companies owning advertising space in railway stations to run an advertisement that said: "If you're not religious, for God's sake say so." This relates to the UK census - BHA is campaigning for people who are not religious to put down "No religion", rather than their cultural religion.
This was a decision by private companies, not a government agency, but the reason given was that ads worded that way would "cause widespread and serious offence"; this kind of reasoning is underpinned by a legal, political, and social climate in which offending religious sensibilities in the slightest has become taboo. Yes, there may be limits to how in-your-face advertisements in these sorts of public places should be ... but for God's sake that wording was nowhere near the limit.
Once again, we need a culture that looks far more favourably on robust freedom of speech.