Also judging from the comments most Redditors aren't aware of how much banning, blacklist and general censorship goes on in addition to the official list. For example, I thought I'd add to the conversation by posting a relevant link to a previous Stone Tapes article. It was on topic, relevant and not malicious, involved in cheating (as far as I know) and I don't think it was spammy (it was the first I Programmer URL submitted by me in many years). It didn't appear and as far as we know I Programmer is banned. There isn't any point in asking the moderators - they usually don't reply, which means that banned sites don't get the opportunity to appeal. OK you may say why whinge about one banned URL, but the article that was banned was critical of Reddit. This is indistinguishable from political or financially motivated censorship.
One other disadvantage of the approach is that is starves some Reddits of material. You can find comments about there being no new and exciting posts in a given Reddit for a while and answering comments of "well I posted some but they never appeared". Censoring due to self posts and supposed misbehaviour reduces the amount of quality material that is available to be redistributed. It cuts off the very life blood of the aggregator.
The current list of banned sites - click to enlarge
It has been suggested that the change in attitude at Reddit is entirely financially motivated. If big sites don't know that they are banned for cheating, how can they be persuaded that the best way to get a Reddit audience is to take some advertising. Another theory is that Reddit is associated with other big content sites and perhaps they are feeling left out of the coverage.
Personally I don't believe that this is the motivation but I'm hard pressed to explain why Reddit feels the need to come clean about a tiny part of their censoring operation.
The really sad part is that the whole thing is based on a misunderstanding. What matters to an aggregator is the quality of the posts that get accepted for attention. Quality is quality, no matter whether it arises from an interested reader or from a self promoter. It is the crowd that is supposed to decide, based on its quality and interest rather than who posted it.
Of course this whole thing goes wrong because it is possible to arrange for up votes that aren't honest. Hence the current draconian and doubtful approach of banning sites that are accused of spammy cheating - the malware bit is thrown in just to make it all seem morally OK.
The correct solution to the problem is to make the moderators into editors - gatekeepers. This is what Slashdot does, and it works reasonably well. If you have editors who are qualified to judge the merit of posts then suddenly it doesn't matter who posts and it can get as spammy as you like and it makes little difference. If crowd votes are only used to raise an article to the attention of an editor earlier than other articles then even cheating stops being a problem. Of course this is difficult to get exactly right. For example voting blocks on Slashdot often push out good stories in favour of less interesting material.
But it works better than censorship.
What matters is the quality of an article and this should be the only determining factor in whether or not it is promoted by an aggregator.
All other concerns are failures of the system.
So why don't they do it?
The simple answer is that it is much easier to be a moderator than an editor. It also seems much more egalitarian to allow crowds to decide and you don't get the blame when things go wrong. For example, when a poor article gets onto Reddit then it is the original poster who gets the flack but on Slashdot is is usually the editor.
Being an editor is tough - everyone hates you.
It also opens up the aggregator to charges of bias. This is exactly what happens in the traditional newspaper industry with its well-known political tendencies. When you have editors bias, or the accusation of bias, is inevitable but it is better than censorship.
So what can be done?
For Reddit probably nothing at all.
Just be aware that as a reader what you are reading is not necessarily the best stuff because some of that is banned.
Reddit and other aggregators need to figure out that their operational model is wrong and, far from being the free and meaningful selection of the crowd, it is an invitation to misuse and any attempt to correct the misuse results in a loss of quality.