StartCom gives up on its Certificate Authority business
The big news recently in the web browser SSL world is that StartCom has officially given up on being a CA because, as I put it on Twitter, no one trusts them any more. As far as I know, this makes StartCom the first CA to go out of business merely because of dubious practices and shady business practices (ie, quietly selling themselves to WoSign), instead of total security failures (DigiNotar) or utter incompetence (ipsCA). I consider this a great thing for the overall health and security of the browser CA ecology, because it shows that browsers are now not afraid to use their teeth.
StartCom is far from unique in having dubious practices (although they may have had the most occurrences). All sorts of CAs have them (or have had them), and in the past those CAs have generally skated by with only minor objections from the browsers; no one seemed ready to actually drop a CA over these practices, perhaps partly because of the collective action problem here. As a result, CAs had very little incentive to not be a bit sloppy and dubious. Are your customers prepared to spend enough money on SHA1 certificates even though you shouldn't issue them any more? Well, perhaps you can find a way around that. And so on.
The good news is that those days are over now, and StartCom going out of business (apparently along with WoSign) shows the consequences of ignoring that. At least Mozilla and Chrome are demonstrably willing to remove CAs for mere sloppy behavior and dubious practices, even if they're still moving slowly on it (IE and Safari are more opaque here). Tighter CA standards benefit web security in the obvious way, and reducing the number of CAs and trusted CA certificates out there is one way to deal with the core security problem of TLS on the web. Unsurprisingly, I'm in favour of this. In practice we put a huge amount of trust in CAs, so I think that CAs need to be held to a high standard and punished when they fail or are sloppy.
Sidebar: My personal view of StartCom
In the past, I got free certificates through StartCom (in the form of StartSSL). Part of StartSSL's business model was giving away basic certificates for free and then charging for revocation, which looked reasonably fair until Heartbleed happened. After Heartbleed, the nice thing for StartCom to do would have been to waive the fee to revoke and re-issue current certificates; this would have neatly dealt with the dilemma of practical reactions to the possible private key compromise. You can probably guess what happened next; StartCom declined to do so. Even in the light of Heartbleed, they stuck to their 'pay us money' policy. As a result, I'm confident that lots of people did not revoke certificates and probably a decent number did not even roll them over (since that would have required paying another CA for new certificates).
From that point on, I disliked StartCom/StartSSL. When Let's Encrypt provided an alternate source of free TLS certificates, I was quite happy to leave them behind. Looking back now, it's clear to me that StartCom didn't actually care very much about TLS and web security; they cared mostly or entirely about making money, and if their policies caused real TLS security issues (such as people staying with potentially exposed certificate keys), well, tough luck. They could get away with it, so they did it.