Hmm Kayla. You do seem to be getting a raw deal.
Firstly, the ongoing
dirty tricks campaign seems to be at the root of your present difficulties. Much like the situation that airline company in Britain - Virgin had. With, British Airways even going up to people queuing for them and telling them how bad the flights were or how *they* could get them cheaper deals etc. Anyway, being companies they took BA to court and it was really bad publicity for BA lol. Obviously court isn't gonna happen here! But Kayla... I do suggest you tackle this clear and present danger head on

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Firstly, the wanting off the website thing. What is it they have a problem with, their photo or their name being on there period? I'd try to find out - call round everyone/text them/set up an anonymous internet poll, whatever. Once you know WHAT's bothering them specifically and WHY, you can start to deal with it.
It's not worth losing members over

. Even if you like you can temporarily just while you're looking into this change the sister page to a blank one with a bar across it saying 'this page is presently offline for operational reasons' or whatever, until it's sorted. As a future idea it might be a thought to have a tickbox on the signup forms for the sorority; where they consent for their likeness to be used on publicity for the group? It may even be just their names - if what I'm guessing is true, whomever is causing trouble is finding out who involved in your group from the site, and then approaching them?
If you don't mind me saying, I do think the dirty tricks smear campaign is worth tackling, soon. My suggestion to you... well actually a few, you can take out anything useful

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Write an open letter to the Chapter President - of every group org on campus. Make it polite but not timid. Be careful with the phrasing, you don't want to come across as too accusing or emotional. Perhaps along the lines of, 'I have learnt recently that some of the greeks at University of Rio Grande may have been approaching members and prospective members of Kappa Gamma Delta and spreading misinformation, or indicating our group is not a group which is going to go anywhere or one worth considering. It is always hard to pin down such matters of course, I felt contacting each of you would be the most fair and reasonable way of tackling this, since it is naturally hard to see specifically where the problem lies. As a new and aspiring sorority we want to work with you, not against you. As President I can assure you that our group bears no ill will toward another. Joint socials, inter-greek events are all something we hope to someday play a part in. Our wish is for all our groups to co-exist happily, perhaps someday with a little friendly rivalry! But we cannot do that if there is bad feeling amonst us. A strong greek spirit is as important to each of the sisters of KGD as I am sure it is to all of you. Presently this is between ourselves I hope we can keep it that way. In closing, I hope we can sort this out happily soon. In unity, Kayla lastname, President, blahetc....
...Hmm, that was worded poorly, but you get the idea?
If that doesn't help... speak to the university agc or whoever, it is possible they have come across this position before and can advise and if necessary even intervene swiftly. Esp. if they're national sororities I doubt their nationals would approve. But it'd be *much* easier ad better to tackle it at a local level to avoid getting a bad reputation - and even better if you can sort it out between the groups yourselves.
I was in a bit of a rush typing as I need to go out, so apologies if my comments above seem the most useless inane words ever!

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I hope it all works out soon

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