Magnet link got filtered when I inserted a link in CKEditor

[KangLing]

I inserted a magnet link in CKEditor textarea field,

magnet:?xt=urn:btih:S0m300DG1BB3R1SH&dn=SOME.RANDOM.FILM.1978.BluRay.720p.x264.DTS-HDWinG

it was supposed to be:

<a href="magnet:?xt=urn:btih:S0m300DG1BB3R1SH&dn=SOME.RANDOM.FILM.1978.BluRay.720p.x264.DTS-HDWinG">a movie name</a>

but the result was:

<a>one movie name</a>

Was the url filtered by the CKEditor module?
How can I avoid this?
Thank you!

Edited April 17, 2015 by diogo
replace the real torrent by a example torrent