Can mobile app startups please stop building SMS invite systems into their apps already? The latest example of a venture-backed startup getting dinged by customers for having spammed their entire address book without permission is Sequoia portfolio company Tribe. Thevideo chat apphit the App Store last year, and had been well-received until now.

With a number of clever twists on standard video chat, Tribe itself is an interesting product. It can add subtitles to video chats and can identify magic words in conversations that are then turned into links to the things you referred to, like directions, the weather, a song, a place, and more.

As of October 2016, the app had been downloaded half a million times, and was seeing around 40,000 daily users. Earlier this year, it also pulled in $3 million in seed funding, led by Sequoia, with the aim of challengingdominant chat apps, like Snapchat and Messenger.

But it doesnt take much to tarnish a brand, and violating users trust is an easy way to lose afollowing.

In Tribes case, its SMS invite system apparently had an issue or, at least, thats the official explanation the company is telling users via its Twitter account.

According to a number of Tribe customers, including those who posted publicly andreached out privately, the app sent out SMS invites to everyone in their address books without permission.

That has resulted in people including those who were only hearing of Tribe for the first time beingspammed with text message invites. And because some victimshad more than one friend on Tribe who was affected by the problem, they received multiple SMS invites throughout the day.

One user reported having received 32 spam invitations, for example, and another said they received up to 47 invites in a single day.

Unlike other apps in the past, like Ever (previously Everalbum), its not clear if Tribe used misleading onboarding screens thattricked users into inviting everyone in their contacts. That would still be shady behavior and the kindthat can get you at least temporarily banned from the App Store. But some users are saying theynever gave the app permission to invite anyone at all. This would make Tribes glitch not just an annoyance, but also an illegal one.

As one tipster told TechCrunch, they received at least 20 texts from people who said they never sent outinvites. Many are also saying this on Twitter.

However, another Tribe user pointed out that the app was pre-selecting all their contacts on a misleading screen, which means those who spammed their address books may have accidentally given the app permission to do so.

The problem is that you cant necessarily prove which is true due to the fact that some partsof an app can be updated without having to go through the App Store review process, and its possible to A/B test different user experiences at the same time.

In any event, people are angry:

Tribes response to customers doesnot include an explanation of what went wrong, or even really, much of an apology.

Instead, the account is individually tweeting back to affected customers a vague message saying thatit fixed an issue on our end. In some cases the accountadds sorry to its tweet, but other times it simply answeredwith a more generic replyinstead.

Thanks for the feedback and we are always looking for ways to improve the Tribe platform, the account said in response to some of the earlier complaints.

While Twitter cant be used to determine how many people were actually spammed duetothis issue, a glitch of this nature should be cause for concern. It violates user trust (and possibly, the law), so it shouldnt get to fly under the radar.

At this point, it would be appropriate for Apple to pullthe app for an additional review to ensure the technical fix is in place, as the startup claims.

Weve reached out to Tribe for comment, but one was not provided at the time of publication. If the companyresponds, well update.

Update, 12/7/2016, 8:30 PM ET

Tribe founder Cyril Paglino responded to say that, yesterday, the companyupdated itsonboarding flow and wastesting some new marketing strategies.

We quickly noticed some issues with a subset of our users. The issue was solved as soon as it was brought to our attention, in few hours, he says. We tooked it very seriously. To be precise, no one has been spammed since the middle of last night.

We never want to violate our users trust and acutely understand how vital that is to our community. We highly value our users privacy, and we always want Tribe to be a place where you can communicate safely and securely.

He further added that the issue affected 0.3% of the user base, and the team has determined that no one sent invites to their entire address books it was capped at 20 invites sent per person.

Update, 12/12/2016, 8:00 PM ET

Tribe has published a formal apology to its blog.

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