Add AT&T to the list of companies yanking ads from Google’s YouTube.

The telco says today that it’s “deeply concerned” that some of its messages “may have appeared alongside YouTube content promoting terrorism and hate.”

“Until Google can ensure this won’t happen again, we are removing our ads from Google’s non-search platforms,” AT&T says.

The move comes a day after Google promised to “tighten safeguards” to help advertisers avoid inadvertently financing “hateful, offensive and derogatory content.”

It also said that YouTube will take “a hard look” at the guidelines that determine “what content is allowed on the platform — not just what content can be monetized.”

Advertisers have long grumbled about the mysterious computer algorithms Google has used to determine where to place spots in order to reach the kinds of audiences brands seek.

Complaints snowballed after The Times of London reported that the computers had linked prominent advertisers’ with neo-Nazi and jihadist content.

Last week Havas Group UK joined major brands including Volkswagen, Toyota and Heinz in freezing their spending on Google and YouTube. The Guardian also withdrew its advertising, saying that Google’s AdX ad exchange placed its messages on “YouTube videos of American white nationalists, a hate preacher banned in the UK and a controversial Islamist preacher.”