Yes, having RC4 enabled is now an instant PCI compliance fail as it has a die-die-die RFC and as a result NIST changed it, on request, to a CVE grade above a 4.0 - https://tools.ietf.org/html/rfc7465 - https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2013-25... - web browsers have already started turning it off.
I worked for a small credit union, and we were beholden to our state auditors, FFIEC guidance, and the like -- but PCI simply wasn't a thing we worried about.
I'm not sure what I can say except not every bank seems to share that view (although as said in other comments, quite a few banks do indeed have paleolithic systems in unexpected places, and that tends to extend to their security practices - I am not able to name any names, but I can wave in the vague general direction of things which involve VAXen, COBOL and DES-and-I-don't-mean-3DES, all of which thankfully predate me). But I'm not exactly familiar with US banking practices (thankfully): did the credit union just not issue any Visa/Mastercard/etc cards? Huh.
I usually complain when some site uses RC4 and I can't access it, but unlike the OP I don't do that via twitter (one reason is that I don't even have an account there).
I've sent 2 emails regarding the use of ONLY RC4 on payment sites in my country, and although such emails aren't always acknowledged they did get fixed after I CC-ed their PCI auditors [1] :)
[1] which you can find publicly on Visa's site at 'PCI DSS validated Member Agent Weblisting' http://www.visaeurope.com/receiving-payments/security/downlo...
That excuse has gone, on two counts. RC4's now thoroughly toast, and Windows XP's unsupported - and now finds itself without any secure ciphers at all.
It's zmap time…
You might want to get ready to change passwords for sites that have used RC4 in the past. Or, despite as much warning as anyone can give, are inexplicably still using it.
I work in security/privacy/premium snake oil trade. Bank security (and software in general) is _usually_ a joke. The main reason for not fucking with a bank is the same why you wouldn't fuck with casinos, or the mob.
Decided to see if I could still log in to any of them about a year ago. Still could on half of them. I left that gig a decade ago.
Oh, and a few of them have no trade limits or risk management.
Boggle.
My contacts were genuinely surprised that this was even possible. But also I was told there would be no contract if I mentioned this to upper management in my report.
There was no contract.
Why wouldn't I, from the other side of the world, from the wifi connection of a coffee shop on the other side of town, bounced through a couple VPNs? It's one thing if I have to walk inside the casino, but the internet isn't like that.
There are many ways to ensure security: one is technical, and another is investigative. The amount of resources a bank can bring to bear on you if you steal money from them is immense - IMO it's just best not to mess with that shit. It may have been true at one time that you could outsmart the banks and get away with it, but there are just too many smart people watching anymore.
By listing the nice bank's twitter first, you're going to cause a backlash against the one that actually responded nicely.
edit: woops, looks like I cant edit it any more. bummer
This one is interesting, as it shows IIS 5.0 (Win2000 SChannel) affected by POODLE TLS.
https://www.ssllabs.com/ssltest/analyze.html?d=nbg.gr
their twitter account is: https://twitter.com/ibanknbg
EDIT: The most effective outreach will be friendly and respectful, if anyone chooses to do this. Also, all the other major greek banks score poorly:
Piraeus Bank Score: F! https://www.ssllabs.com/ssltest/analyze.html?d=www.piraeusba... twitter:https://twitter.com/skepsouprasina
Alpha Bank: B https://www.ssllabs.com/ssltest/analyze.html?d=www.alpha.gr&... twitter: https://twitter.com/alpha_bank
Eurobank: Score: F! https://www.ssllabs.com/ssltest/analyze.html?d=eurobank.gr twitter:https://twitter.com/Eurobank_Group