In short, yes. Tagboard has legal authority to publicly display social media content and here's how.
Every social network has users accept a 'Terms of Service/Use' or 'Statement of Rights and Responsibilities' that gives the social network and its PARTNERS a license to share and display public photos. These partners include social media search and display platforms like Tagboard, who legally pull the content through the networks’ APIs, and comply with their requirements for partnership – such as, including network logos and author avatars on all posts. In addition to this explicit right, the Tagboard platform only ingests social posts which have been marked as Public and remain on the source network.
Don't take our word for it though. Here are excerpts from, and links to, the big three network's complete terms of service (TOS):
"When you publish content or information using the Public setting, it means that you are allowing everyone, including people off of Facebook, to access and use that information, and to associate it with you (i.e., your name and profile picture)."
"By displaying or publishing ("posting") any Content on or through the Instagram Services, you hereby grant to Instagram a non-exclusive, fully paid and royalty-free, worldwide, limited license to use, modify, delete from, add to, publicly perform, publicly display, reproduce and translate such Content, including without limitation distributing part or all of the Site in any media formats through any media channels, except Content not shared publicly ("private") will not be distributed outside the Instagram Services."
"By submitting, posting or displaying Content on or through the Services, you grant us a worldwide, non-exclusive, royalty-free license (with the right to sublicense) to use, copy, reproduce, process, adapt, modify, publish, transmit, display and distribute such Content in any and all media or distribution methods (now known or later developed). This license authorizes us to make your Content available to the rest of the world and to let others do the same."
In most standard redisplay use cases, displaying social media content on a website or at an event does not remove the content from the protection of the network’s TOS above, provided you do so through a partner of the network--Such as Tagboard and use the content for adjacent marketing. Adjacent marketing means the content exist near direct advertising or marketing, but the content itself is not a part of an advertisement. For UGC in a direct marketing campaign please see this document: https://support.tagboard.com/docs/redisplaying-user-generated-content