Sponsored tweets showing up in your timeline is now an unfortunate but expected part of using Twitter. However, another of the company's sponsored ad units is leaving some high-profile Twitter users unhappy. As reported by Marketing Land, a sponsored MasterCard account started showing up in the "following" list of William Shatner, Dwayne Johnson, Barack Obama, Lady Gaga, and even Visa. This essentially made it look like these users were following MasterCard — something that left Shatner rather peeved. "Do you understand that by implying that I follow these companies that it appears to be an endorsement?" read one Shatner tweet directed at Twitter co-founder Jack Dorsey and the company's "trust and safety" account.

.@jack @safety Do you understand that by implying that I follow these companies that it appears to be an endorsement? — William Shatner (@WilliamShatner) December 30, 2014

Shatner also noted that blocking the offending accounts would remove them from a user's "following" list, and indeed it seems that Shatner has cleaned up his list accordingly, as have the other people who've seen this happen. It's also entirely possible that MasterCard pulled its promotion after the backlash started making its way around the internet (or the promotion simply ended). I actually noticed the MasterCard account in my following list this morning, but it has since disappeared.

"I am going to reevaluate the time I spend on Twitter going forward."

However, it's worth noting that promoted accounts in a follower list on Twitter isn't a new feature or ad promotion the company is testing — we've learned that Twitter has been offering this since early 2013. This just might be the most high-profile example of someone noticing and using his reach to point it out to other Twitter users. Either way, it appears that random accounts showing up in your followers list isn't something a lot of Twitter users have seen before or are very comfortable with — and as more and more internet companies turn to "native" advertising, they're facing questions about ads like this that can appear deceptive. These ads really do make it appear like Shatner and The Rock were following MasterCard, and a small "promoted" label doesn't really explain to users what exactly is happening. As for Shatner, he says the incident is going to cause him to "reevaluate" how much he uses Twitter going forward.