Buying followers on Twitter has always been seen as one of those shady, underground practices that's easy to do, but frowned upon by the masses.

But that practice had seemingly gone mainstream early Saturday morning, when accounts like @PlayStation, @Viacom, @XboxSupport, @NTSB, @TheNewYorker, @TheNextWeb, the Red Cross (@ICRC) and @Money had "started aggressively pushing ways to help you obtain more followers for free," according to Engadget.

But upon further inspection through popular Twitter client Tweetdeck, it appears all of the tweets had been sent out via the Netherlands-based Twitter Counter (@thecounter), which is a tool that "provides statistics of Twitter usage and tracks over 14 million users … and sells featured spots on its website to people who want to gain more followers," according to its site.

The tweets began rolling out with malicious links at around 1 a.m. ET Saturday, promoting various websites inviting users to get more followers just by clicking.

In addition to the companies and organizations listed above, the U.S. National Transportation Safety Board (NTSB) was also affected, as well as some politicians and celebrities including Charlie Sheen, Lionel Messi, astronaut Leland Melvin, and Minnesota Governor Mark Dayton. A large number of other users were also affected but the number is unknown.

The tweets promoting the follower-buying sites have since been deleted. Twitter Counter confirmed Saturday that its service had been hacked.

"We can confirm that our service has been hacked; allowing posts on behalf of our users! We have launched an investigation into this matter," tweeted Twitter Counter on Saturday morning.

Shortly afterwards Twitter Counter tweeted that "the hackers CANNOT post on our users' behalf anymore."

"We ensure the privacy of our users' information. We do not store credit card information and we do not keep Twitter account passwords," Twitter Counter added, in a subsequent tweet.

As Engadget advised, the incident simply serves as an extra reminder to change your password often, make your passwords difficult to guess, don't share it with anybody ever, and check any apps or services you might have linked purposefully or accidentally to your social media accounts. As was possible in this case, if one of them gets hacked, your account could be at risk, as well.