diff --git a/text/abstract.tex b/text/abstract.tex
index 507bff8..230b98d 100644
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@@ -4,7 +4,7 @@
 % \mk{D'accord :( }
 Sensors, portable devices, and location-based services, generate massive amounts of geo-tagged, and/or location- and user-related data on a daily basis.
 The manipulation of such data is useful in numerous application domains, e.g.,~healthcare, intelligent buildings, and traffic monitoring.
-A high percentage of these data carry information of user activities and other personal details, and thus their manipulation and sharing arise concerns about the privacy of the individuals involved.
+A high percentage of these data carry information of user activities and other personal details, and thus their manipulation and sharing raise concerns about the privacy of the individuals involved.
 To enable the secure---from the user privacy perspective---data sharing, researchers have already proposed various seminal techniques for the protection of user privacy.
 However, the continuous fashion in which data are generated nowadays, and the high availability of external sources of information, pose more threats and add extra challenges to the problem.
 % \kat{Mention here the extra challenges posed by the specific problem that you address :  the Landmark privacy}