background image should never ever be use like this
it should be a proper img tag with alt username
theres lots more bad code standards but these are some i find in quick looking at some things
the avatar image on profiles is a background image ???
i bet is the same for groups etc
in /ow_system_plugins/base/views/avatar_change line 208
<div style="background-image: url({$image.url});" class="ow_photo_item"> this should not be a background image
/ow_system_plugins/base/views/avatar_user_list_select line 39
avatar=$avatars[$user.id] no alt tags
/ow_system_plugins/base/views/floatbox_user_list line 37
avatar=$avatars[$user.id] no alt tags
/ow_system_plugins/base/views/my_avatar_widget line 5
<a href="{$avatar.url} " class="ow_my_avatar_username"><span>{$avatar.title}</span></a> no alt tags
/ow_plugins/birthdays/views/components/my_birthday_widget line 2
<img src="{$ballonGreenSrc}" /><br /> no alt tags
/ow_system_plugins/base/views/users line 33
avatar=$avatars[$id] no alt tags
ow_plugins\contact_importer\views\components/widget line 20
<img src="{$b.iconUrl}" /> no alt tags
\ow_plugins\friends\views\controllers/list_index line 38
avatar=$avatars[$id] no alt tags