Hi,
you can use a text field type and set these options:
Format Allowed: Custom
Custom Format: HERE A REGEX TO VALIDATE INPUT

So this will be regular field and there are no options to display Social Media Logo (like FB logog, LinkedIn logo, ..)

How will that be displayed on the page? Will it show as big hyperlink?

Hi,
you can show this field as HTML delimiter field type, in HTML delimiter you can use our Content plugin, so for example:
- Set your text field type to show only in registration/edit profile page
- Create an HTML delimiter field type and put this code in description:

<a href="/{user text_field_alias displayed raw}">Link to Facebook (or image)</a>

In the profile you will show only HTML delimiter field type that contain a link to social page.

Docs about HTML delimiter field type: http://docs.easy-profile.com/index.php/article/html-delimiter-field-type
Docs about content plugin: http://docs.easy-profile.com/index.php/article/content-plugin

Alternatively you can use a Joomla Custom module to show this link instead in an HTML delimiter field type.

NOTE: when you set HTML in the description some editor can replace some code because do not recognize {user text_field_alias displayed raw} as link, so we recommend to disable HTML editor