Answers.Body: <p>Did you check your log files to see if the fraudulent Event registrations originate from the same IP (or similar)? </p>
  
  <p>If so then block that IP (or entire subnet) so that it can no longer access your server.</p>
  
  <p>For those using iATS Payments there is another handy anti-fraud measure: you can block credit cards originating from certain BIN countries to go through;</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-09-14T13:03:24.300Z
Answers.LastActivityDate: 2017-09-14T13:03:24.300Z
Answers.UserDisplayName: KarinG - Semper IT
Answers.Body: <p>It's hard to answer this question without more information, but I'll give it a shot.</p>
  
  <p>My first approach would be to write a CiviCRM extension using <a href="https://wiki.civicrm.org/confluence/display/CRMDOC/hook_civicrm_validateForm" rel="nofollow noreferrer">hook_civicrm_validateForm</a>.  This would give a result similar to if someone left out a required field - it would reload the page with an error.</p>
  
  <p>If your goal is instead to allow them to register (and it's a free event) but not see the results, Michael M's suggestion of a CiviRule to delete the event after it's created may work.</p>
  
  <p>If your goal is something else - e.g. to fake a successful event - you'd have to give more details, but is likely to be more difficult.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2016-12-04T16:15:21.870Z
Answers.Text: Thanks for your response. I don't have much more info to provide, unfortunately. This is a specific gmail address used to register participants for an event. Close to the event they cancel and request a refund, as "their immigration application didn't succeed." It's happened enough that we're aware it's a scam. Because the payment goes through immediately via Paypal, it seems legit and CIVICRM processes it. What we want to do is block it. The party involved could start using another email address (participant names are always unique) so I guess any approach might be a short term solution.
Answers.UserDisplayName: Chris Hutcheson
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2016-12-05T17:45:11.430Z
Answers.Text: @ChrisHutcheson How annoying!  The `validateForm` hook is a good choice then, because it prevents the form from being submitted.  You could also use the `postProcess` hook to fake a successful event registration, but kill it before it reached PayPal.  They'll know they didn't succeed when the card isn't charged though.
Answers.UserDisplayName: Jon G - Megaphone Tech
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2016-11-18T00:23:40.900Z
Answers.LastActivityDate: 2016-11-18T00:23:40.900Z
Answers.UserDisplayName: Jon G - Megaphone Tech
Body: <p>We have had a particular email address used for registering a number of different participants for workshops in CIVIEVENT - and subsequently cancelling - that we believe is an immigration scam. Wondering if there is a way to disable this particular address from registering.</p>
  
  <p>Thanks!</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2016-11-17T20:40:50.443Z
Comments.Text: I wonder if you could create an appropriate rule using CiviRules (I thought this was better as a comment rather than an answer, since it is so light on detail).
Comments.UserDisplayName: michaelmcandrew
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2016-12-04T16:10:59.687Z
Comments.Text: Thanks for this - I'll give the rules a try. For the moment we've also blacklisted the sender's email address in our hosting setup. It won't eliminate the registration problem, but it might give them a hint.
Comments.UserDisplayName: Chris Hutcheson
Tags: <email><user>
Title: Blocking specific email users from registering for events
ThreadText: # Blocking specific email users from registering for events
  
  (Asked by: username_0 on 2016-11-17)
  
  We have had a particular email address used for registering a number of different participants for workshops in CIVIEVENT - and subsequently cancelling - that we believe is an immigration scam. Wondering if there is a way to disable this particular address from registering.
  
  Thanks!
  
  **Tags:** email, user
  
  > **Comments:**
  > **username_1**: I wonder if you could create an appropriate rule using CiviRules (I thought this was better as a comment rather than an answer, since it is so light on detail).  
  > **username_0**: Thanks for this - I'll give the rules a try. For the moment we've also blacklisted the sender's email address in our hosting setup. It won't eliminate the registration problem, but it might give them a hint.  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_2 on 2017-09-14. Score: 1
  
  Did you check your log files to see if the fraudulent Event registrations originate from the same IP (or similar)?
  
  If so then block that IP (or entire subnet) so that it can no longer access your server.
  
  For those using iATS Payments there is another handy anti-fraud measure: you can block credit cards originating from certain BIN countries to go through;
  
  
  ---
  
  ### Answer by username_3 on 2016-11-18. Score: 0
  
  It's hard to answer this question without more information, but I'll give it a shot.
  
  My first approach would be to write a CiviCRM extension using [hook\_civicrm\_validateForm](https://wiki.civicrm.org/confluence/display/CRMDOC/hook_civicrm_validateForm). This would give a result similar to if someone left out a required field - it would reload the page with an error.
  
  If your goal is instead to allow them to register (and it's a free event) but not see the results, Michael M's suggestion of a CiviRule to delete the event after it's created may work.
  
  If your goal is something else - e.g. to fake a successful event - you'd have to give more details, but is likely to be more difficult.
  
  > **Comments:**
  > **username_0**: Thanks for your response. I don't have much more info to provide, unfortunately. This is a specific gmail address used to register participants for an event. Close to the event they cancel and request a refund, as "their immigration application didn't succeed." It's happened enough that we're aware it's a scam. Because the payment goes through immediately via Paypal, it seems legit and CIVICRM processes it. What we want to do is block it. The party involved could start using another email address (participant names are always unique) so I guess any approach might be a short term solution.  
  > **username_3**: @username_0 How annoying!  The `validateForm` hook is a good choice then, because it prevents the form from being submitted.  You could also use the `postProcess` hook to fake a successful event registration, but kill it before it reached PayPal.  They'll know they didn't succeed when the card isn't charged though.  
  
  ---
  
  