This was posted on their subreddit...
We are getting hit hard by a ddos attack. Hopefully it will stop soon , they are just hurting your service. Everyone's bitcoins that were already sent are still going out. You should have your coins soon. -GramsAdmin Update
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Grams is still being DDos. There has been no extortion demands. We don't know who is doing it. If anyone has information to who is doing it , please come forward and you will be rewarded if the information pans out. In the mean time, if anyone has Bitcoin in their grams account which they need to withdraw, email me at grams@sigaint.org with your grams username , sign the message so I can verify it is you, and I will get your coins to you.
Thanks, - -GramsAdmin -----BEGIN PGP SIGNATURE----- Version: BCPG v1.47 iQE+BAEBAgAoBQJWtNguIRxHcmFtcyBBZG1pbiA8Z3JhbXNAbGVsYW50b3Mub3Jn PgAKCRBTVTZOyfyXGZBbCACw+7SpaoN4WcRejpbg+5LViL8WmN7gKTA3ug+CRgiX vuiiJB4BkCKvF5KRD68zCRHRL2cDpXDzPGIRq5f1Z6eoCbkCjMDQ53Jy/SCMhSUO +5tsU46L552vPiaHRO1yHmMjQUBjrUEHzp+lrsPFwBdgArB/ZP6g57puheJqYNs7 mKVZF2Rlb35w/GwOGN+xmkJ8GNccTqKNFTk5d5uB7GKXK6Vt4z1rfiLoGyJdaBSA ogBJhLnRrHsz/FP9a9kd1N5wPggv/F1B26DK8xw6wZ07EDyh53txjf7Du4HzSFWN 7fk49EAdq2KO68pBEr98yAcRabZWfxvjQeG06hkhHTfB =Nywb -----END PGP SIGNATURE-----
Link to actual post by grams admin in /r/grams