A large-scale hack hit Twitter on Wednesday, affecting hundreds of high-profile accounts, including those belonging to news organizations like BBC North America and Forbes. The accounts posted identical spam messages that were written in Turkish and included swastikas and Nazi hashtags. The hack also swapped out the accounts’ profile photos.

This isn’t good, right? pic.twitter.com/nvxWYAutsO

— Rob Lopez (@R0BaTO) March 15, 2017

Like many Twitter “hacks,” Wednesday’s breach wasn’t a result of hackers going after Twitter directly. Instead, the hack was a result of a vulnerability in third-party app Twitter Counter, a popular Twitter data analytics tool that was also hacked four months ago. Both Twitter Counter and Twitter itself acknowledged the hack and say they’re addressing the problems.

We’re aware that our service was hacked and have started an investigation into the matter.We’ve already taken measures to contain such abuse

— TheCounter (@thecounter) March 15, 2017

Connected apps are perennial security concerns. Some apps only require permission to read users’ Twitter feeds, but others, such as Twitter Counter, also have write permissions, which gives them the green light to tweet from accounts that use them. With every connected app, each a link weaker than Twitter itself, comes a new security vulnerability, and the potential for abuse is compounded by the ease in which new apps can be added. This results in a sort of “permissions creep” in which many apps are added over time, but few are removed. (True confession time: We checked the official @NiemanLab Twitter account — it has over 80 connected apps, some of which have had read and write permissions since 2009.)

Twitter says it has already removed Twitter Counter’s permissions, but the dustup should serve as yet another reminder of why it’s vital that news organizations, often the targets for hacks, periodically clean up their Twitter permissions of any old and unused apps. It’s a short process: From Twitter’s Settings and Privacy section, click Apps, which will list all the apps with third-party access. Clicking “revoke” will remove the app’s permissions. Twitter has more info here.