I've tried this.
grep -r thanks * slave-iv
grep: invalid option -- '@'
Usage: grep [OPTION]... PATTERN [FILE]...
Try `grep --help' for more information.
Here's what the directory looks like. They're log files from pidgin.
ls -1
-100000139702926@chat.facebook.com
-100001138571192@chat.facebook.com
-1021869012@chat.facebook.com
-12120618@chat.facebook.com
-1251570038@chat.facebook.com
-1269333626@chat.facebook.com
-1394365872@chat.facebook.com
-1657581332@chat.facebook.com
-211203163@chat.facebook.com
-505152641@chat.facebook.com
-549333601@chat.facebook.com
-557177029@chat.facebook.com
-573222477@chat.facebook.com
-584051302@chat.facebook.com
-65000319@chat.facebook.com
-663869224@chat.facebook.com
-664953132@chat.facebook.com
-755682783@chat.facebook.com